Category Archives: FOS

New research links FOS and Bone Health

A recent study published in the Journal of Nutrition suggests a link between fructooligosaccharides (FOS) and bone health. It indicates that combining a calcium supplement with FOS is more effective than taking a calcium supplement alone (1).

The two-year study followed 300 post-menopausal women and measured markers of bone health. The women were randomly divided into three groups. One group of women were given a daily calcium supplement, while a second group were given a combination of calcium and FOS . The third group were given a placebo supplement. At the end of the study, measures of bone turnover and bone density were taken.

At the end of the study, there were no significant differences in bone density between any of the three groups. However, the results showed that the combination of FOS and calcium had the greatest effect on bone turnover.

Bone is constantly being broken down and rebuilt. The rate at which this happens is known as ‘bone turnover’ and is a known indicator of bone quality. The change in bone turnover markers in the women taking both FOS and calcium indicates ‘a more favourable bone health profile’ according to the researchers in this study.

FOS seems to enhance calcium absorption in the large intestine, and the researchers suggest that this is the reason for its effect on bone health. These findings certainly support the need for more research in this area, particularly for vulnerable groups such as postmenopausal women.

More about FOS

FOS or prebiotics are found in chicory root, jerusalem artichoke, asparagus, leeks, onion, beans, peas and lentils.
FOS or prebiotics are found in chicory root, jerusalem artichoke, asparagus, leeks, onion, beans, peas and lentils.

FOS is a prebiotic nutrient found in plant foods. Prebiotics are not digested, and simply pass through the body. In doing so, they act as ‘food’ for healthy bacteria in the bowel, boosting numbers of health-promoting acidophilus and bifidobacteria, and crowding out disease-causing bacteria. As well as improving calcium absorption, FOS also supports both digestive and immune health.

High concentrations of FOS or prebiotics are found in chicory root, jerusalem artichoke, asparagus, leeks, onion, beans, peas and lentils. FOS can also be taken in supplement form, and its sweet taste means that it works well mixed into oatmeal, yoghurt or smoothies, or simply used as a low-calorie sweetener to enhance flavour.

In the UK, most of us average an intake of around 12g of fibre each day – only half of the recommended amount. More research is still needed in the area of FOS and bone health. In the meantime, increasing fibre intake, and prebiotic foods in particular, seems a sensible measure to ensure the recommended intake for optimal health.


Slevin, M, Allsopp P, Magee M, Bonham V, Naughton J, Strain M, Duffy J, Wallace E, McSorley E. 2014. “Supplementation with Calcium and Short-Chain Fructo-Oligosaccharides Affects Markers of Bone Turnover But Not Bone Mineral Density in Postmenopausal Women”. Journal of Nutrition Jan 2014


Can increasing the amount of fibre in the diet impact body weight?

A high fibre diet has been shown in many studies (1) to be linked to a reduced risk of cancers, heart disease, diabetes and obesity.

Recently published data (2) has found that a higher intake of dietary fibre may play a beneficial role in the prevention of body weight gain and gain in waist circumference measurement.  The authors of this study, published in the American Journal of Clinical Nutrition, looked at the association of dietary fibre with changes in weight and waist circumference.  The research involved over 89,000 individuals ages 20-78 who were free of cancer, cardiovascular disease, and diabetes at the beginning of the study.  The participants were followed for 6.5  years.  The results show (2) that a higher intake of total fibre was associated with a reduced likelihood of weight and waist circumference change when compared to low intake of total dietary fibre. 

Fibre may be having an impact on weight through various indirect methods.  Fibre is generally quite filling, it promotes satiety and hence decreases feelings of hunger – eating a fibre rich diet may therefore reduce daily calorie consumption.  In addition to this, foods which are high in fibre, such as vegetables and pulses/beans, tend to be bulky (high volume) and low in calorie content and have the added benefit of being packed with vitamins, minerals and bioflavonoids (bio-active plant chemicals)

Here in the UK the majority of adults are not meeting the recommended daily intakes of 18g of fibre.  The National Diet and Nutrition Survey (3) reported that 72% of men and 87% of women were not meeting the recommended 18g of NSP per day.  In 2000/2001, the average daily intake of fibre was 15.2g for men and 12.6g per day for women!  The recommended amount of 18g per day was set in 1991 and is lower than most of the recommended intakes elsewhere in the world.  Many health professionals would advocate a daily fibre intake of 25-35g daily.  A healthy balanced diet rich in whole grains, pulses, beans, lentils, fruit and vegetables is a great way of increasing intakes.

There are two types of fibre: insoluble fibre and soluble fibre.  Insoluble fibre cannot be digested by the body, it helps to promote fullness and also aids the removal of waste from the body.  Thus is keeps the bowels healthy and prevents against constipation.  Vegetables, fruits and wholegrains contain a lot of insoluble fibre.  Soluble fibre can be partially digested and may help to reduce the amount of cholesterol in the blood. Good sources of soluble fibre include oats and pulses such as beans and lentils.

In addition to the impact of fibre on satiety and potentially on weight, as mentioned above, low fibre intakes are associated with constipation and other gut diseases such as diverticulitis.  For more information on the health benefits of dietary fibre please visit the British Nutrition Foundation website and the government Eat Well website

If you feel that you are regularly not getting enough fibre from your diet it is important to see if you can find ways to increase the amount of vegetables, fruits, beans/pulses and wholegrains into daily meals.  There are also many fibre supplements available but these lack the other nutritional benefits provided from plant foods (e.g. vitamins and minerals) that plant foods contain.  One supplement that may be worth considering is FOS, fructo-oligosaccharides, since this provides a form of fibre but is also a prebiotic and hence has other health benefits.  A prebiotic is a food that stimulates the growth of the beneficial bacteria already present in the colon.  In October I wrote a post about evidence linking prebiotics to reduced appetite and increased satiety.  Just 5g daily could be beneficial for a number of reasons as well as boosting fibre intakes.


(1)Buttriss JL & Stokes CS.  2009.  Dietary fibre and health: an overview.  Nutrition Bulletin.  33:186-200
(2)Huaidong Du et al.  2010.  Dietary fiber and subsequent changes in body weight and waist circumference in European men and women.  American Journal of Clinical Nutrition.  91: 329-336
(3) Henderson L et al.  2003.  The National Diet and Nutrition Survey: Adults aged 19-64 years.  HMSO London
Written by Ani Kowal


Can the bacteria in our digestive system influence body weight issues?

On Thursday I went to the Nutrition Society Summer meeting at the University of Surrey.  The five day conference had concentrated on various aspects of over- and undernutrition.  The symposia that I attended were exceptionally interesting and thought provoking.  One of the presentations(1) was given by Dr Paul Kelly of Barts and London School of Medicine and Dentistry.  He was speaking about the microorganisms in the digestive system and links to diarrhoea in individuals in developing countries.  However, he briefly mentioned an animal study that linked the makeup of the bacteria in the digestive system and a propensity to obesity.  This got me thinking about whether that link was present in humans.  Upon returning home I had a search through the medical databases to see if there was any literature to support these thoughts.

Can bacteria in the gut have anything to do with developing excess body weight or obesity?

There seems to be a fair amount of recently published interest in the topic of digestive bacterial balance and the links to obesity and overweight (e.g. 2,3,4,5,6).  For many years the large intestine was thought only to be important for water absorption and storage of waste.  However, the adult human gut contains up to 100 trillion microbial organisms (including bacteria and yeasts) collectively known as the microbiota or microbiome.  These gut bacteria seem to have an effect on the entire body and not just the health of the digestive system.

Obesity is a complex disease involving many factors with no miracle cure and no easy solutions – I am not about to disillusion anyone by inferring that bacterial balance is a major factor and probiotics (supplemental good gut bacteria) are the cure.  However, gut bacteria may well be having some kind of impact on the development of excess body weight in some people.  What we eat does affect the composition of the microorganisms that are present in our digestive systems and in turn these microorganisms can have an effect on the health of our body.  A review published in French this year (2) looked at the evidence which suggests that the gut microorganisms are linked with metabolism and inflammation, and could be involved in type 2 diabetes, metabolic syndrome and obesity.

An extensive review published in America last year (3) looked at a wide range of evidence in order to investigate the potential role of the gut bacteria in the development of obesity. The authors of the paper found that interactions among the microorganisms in the gut appear to have complex effects in the human body and that the gut organisms may have an important role in regulating weight and may also be partly responsible for the development of obesity in some people.  Evidence suggests that our gut microorganism environment is established within the first year of life and then remains fairly constant through adulthood.  However dietary factors, infections and antibiotic use may lead to long-term changes.

The gut bacteria may be acting on weight via effects on: calorie utilisation from food, metabolism, inflammatory responses, hormone regulation or other means and evidence does suggest that obese and lean individuals seem to have different composition of gut bacteria (3).  A study published last year (4) followed children from birth to age 7 years.  Children of normal weight and those who were overweight had significant differences in their gut bacterial composition suggesting that an important link between bacterial balance and obesity development possibly via inflammatory pathways.  The authors conclude that their findings may offer “new possibilities for preventive and therapeutic applications in weight management”.

Can modifying the gut bacteria through diet and/or probiotic or prebiotic (such as FOS, fructooligoosaccharides) supplements have an impact on body weight?

The review paper (3) emphasises that the best, nonsurgical, strategy for reversing obesity in the population seems to be to promote small but long-term changes in diet and physical activity.  The authors go on to say that further evidence with regards bacterial gut balance is needed but that microorganisms may well be influencing obesity.  They suggest that probiotic and prebiotic supplements may be useful in order to positively change the gut bacterial balance and help prevent and treat overweight but that these manipulations should clearly not be viewed as a substitute for a healthy diet and exercise.

Prebiotics act as food for the good ‘friendly’ bacteria in the digestive system and studies (3) suggest that prebiotics in the diet may reduce our energy and food intake, increase satiety, reduce hunger and appetite and reduce total daily calorie intakes.  FOS may also have effects on blood sugar balance in the body.

Probiotics, live ‘friendly’ bacterial supplements, may also change the bacterial balance of the digestive system and have an effect on overall health in the body, but studies in humans and the links to weight control are lacking.  An interesting study presented at a conference this year (6,7) found that probiotics during and after pregnancy may help prevent the development of obesity after birth.  The study found that at 1 year after giving birth, 25% of women given probiotics along with dietary counseling had central obesity based on that definition, compared with 43% of women given diet advice alone. In a press release the author stated that “This is the first study showing that probiotics-supplemented diet during pregnancy and breastfeeding influences the adiposity [fat mass]of women over the 12-month postpartum period,” Further evidence is needed but the author said that modification of bacterial balance in the intestines with probiotic supplements “together with a balanced diet may offer a reasonably economic, practical, safe and potentially successful method to be used with other lifestyle-related factors in controlling obesity” (7).

Further conclusive evidence needed, however prebiotics (such as FOS) and probiotics do seem to positively change the composition of bacteria in our digestive systems and affect overall health.  Supplements are readily available but should not be seem as a quick-weight loss fix.  A healthy diet and lifestyle is of paramount importance for weight control and overweight prevention and treatment.

(1)Dr Paul Kelly.  2009.  Symposium 4: Gut function: effects on over and under-nutrition.  Nutrition, intestinal defence and the microbiome.  The Nutrition Society Summer Meeting.  University of Surrey.  Thursday 2nd July 2009.
(2) Pataky Z et al.  2009.  Gut microbiota, responsible for our body weight?  Rev Med Suisse.  5:662-664 [Article in French]
(3) DoBaise JK et al.  2008.  Gut microbiota and its possible relationship with obesity.  Mayo Clinical Processings.  83:460-469
(4) Kalliomaki M et al.  2008.  Early differences in fecal microbiota composition in children may predict overweight.  Am J Clin Nutr.  87:534-538
(5) Tennyson CA &Friedman G.  2008.  Microecology, obesity and probiotics.  Curr Opin Endocrinol Diabetes Obes.  15:442-447
(6) Kirsi Laitinen, nutritionist and senior lecturer at the University of Turku in Finland.  Study findings presented at 17th European Congress on Obesity 6-9 May 2009 held in Amsterdam
(7)  Anthony J. Brown, MD.  2009.  Probiotics may help ward off postpartum obesity.  2009-05-08 15:24:34 -0400 (Reuters Health).

Written by Ani Kowal


Natural solutions for an uncomfortable problem

Talking about bowel habits is not something we often do but if constipation is affecting your life it can be quite uncomfortable and even upsetting.  Thankfully there are plenty of ways to ease the problem without resorting to pharmaceutical laxatives.  Constipation is usually defined as a change in daily bowel patterns, particularly a decrease in the number or consistency of bowel movements, or pain or difficulty passing stools

Prebiotics and probiotics

Previously (in August) I wrote extensively about prebiotics, probiotics and synbiotics with regards IBS (irritable bowel syndrome).  Unsurprisingly these same agents work very well in the prevention and treatment of constipation.  By positively changing the bacterial makeup of the gut they help to keep the digestive system functioning efficiently.  Prebiotics also act as a source of fibre, which adds bulk to stools and absorbs water to help eliminate waste efficiently and painlessly.

As you will probably be aware, there are many yoghurts now available on the market which contain both pre-biotics and pro-biotics.  There is evidence from recent trials (1,2) to suggest they are effective in treating constipation.  A recent study (1), published in march, found that consumption of the yoghurt was associated with increased frequency of bowel movements, a reduced perception of straining effort and a reduced perception of pain associated with defecation.

Inulin, a type of prebiotic powder supplement, has been shown to increase the number of good bacteria in the gut as well as reducing constipation better than a traditionally used lactose laxative (3).  A supplement containing both prebiotics and probiotics has also shown good results in the treatment of constipation (4).   Taking a daily symbiotic supplements, those containing prebiotics and probiotics, may well be useful for the treatment and prevention of constipation and the efficient functioning of the digestive system.  There is also emerging evidence, that I have discussed previously, which indicates that a good bacterial balance in the gut may affect the immune system of the whole body, so a daily supplement may help to keep you feeling great!

Artichoke leaf extract

As well as its usefulness in treating IBS, artichoke leaf extract seems to be helpful in alleviating constipation.  One study(5) found that 71% of constipation patients experienced improvement using artichoke leaf extract for 6 weeks.  If you are suffering from this uncomfortable condition you may wish to try an ALE supplement for a few weeks to see if it brings relief and normalises daily bowel habits.


Previously I have mentioned how, in the UK, we tend to fall short of the daily recommendations for fibre provision.  Many of us reach only 12g/day, the recommendation is for at least 18g/day with many health professionals recommending around 25g/day.  Fruit and vegetables provide lots of fibre, as well as all the other nutrients packed within them.  We would all do well to reach a minimum of five portions daily.  Fibre provides bulk in the digestive system, this then absorbs water making stools easy to pass and preventing constipation.  A recent study(6) in children found that constipated children had significantly lower intakes of dietary fibre than non-constipated counterparts which was attributable to under-consumption of plant foods.

Regularly eating the recommended portions of a variety of fruit and vegetables may prevent the occurrence of constipation.  Increasing intakes if constipation is already present may also help to ease and clear the problem.  Two studies (7,8) have found that eating a couple of kiwi fruit a day is helpful in the treatment of constipation.

You may wish to consider a supplemental source of fibre as a short term measure for treating constipation.  One source of fibre which seems to be helpful is flaxseeds (9,10).  If you want to try this form of fibre I would recommend buying a ground flaxseed, sometimes called linseed, supplement (or grinding the seeds yourself at home), these are easier on the digestive system and the grinding will also help to release essential omega 3 fatty acids within the seeds which adds to the nutritional benefits.  A table-spoonful of ground flax (about 15-25g) a day will probably help to ease constipation within a couple of days.  A teaspoon a day (around 5g) could be useful in prevention or re-occurrence of constipation and may be particularly useful if you feel your daily fibre intake is habitually low.


Drinking enough (around 1.5L) water daily is important in the prevention and treatment of constipation.  Water is absorbed by fibre in the digestive system and adds bulk to the waste making it easier to pass.  One study (11) found that including 25g of fibre from food in the daily diet was very helpful in treating constipation and that the effect was significantly enhanced by increasing fluid intake to 1.5-2.0 litres/day.  Another study (12) concluded that fluid loss (via diarrhoea and laxative use), fluid restriction, poor hydration and dehydration increased constipation. It is very important to maintain hydration to prevent constipation.

Cow’s milk

Finally I would like to suggest that if your child (up to age 10) is suffering from regular bouts of constipation it may be a good idea to ask your GP to do a test for allergy to cow’s milk.  There are studies (13,14,15) to suggest that chronic constipation occurs as a result of cows milk allergy in some children.  There is also a lot of anecdotal evidence to back this up.  It is very important that you see your GP for the allergy test, never try elimination diets at home without the involvement of a health professional.



(1)De Paula JA et al.  2008.  Effect of the ingestion of a symbiotic yoghurt on the bowel health of women with functional constipation.  Acta Gastroenterol Latinoam.  38:16-25
(2)Sairanen U et al.  2007.  Yoghurt containing galacto-oligosaccharides, prunes and linseed reduces the severity of mild constipation in elderly subjects.  Eur J Clin Nutr.  61:1423-1428
(3) Kleessen B et al.  1997.  Effects of inulin and lactose on fecal microflora, microbial activity, and bowel habit in elderly constipated persons.  Am J Clin Nutr.  65(5):1397-1402.
(4)Amenta M et al.  2006.  Diet and chronic constipation. Benefits of oral supplementation with symbiotic zir fos (Bifidobacterium longum W11 + FOS Actilight).  Acta Biomed.  77:157-162
(5) Gebhardt R.  1996.   Antidyspeptic and lipid-lowering effects of artichoke leaf extract.  Journal for General Medicine.  2
(6)Lee WT et al.  2008.  Increased prevalence of constipation in pre-school children is attributable to under-consumption of plant foods: A community-based study.  J Paediatr Child Health.  44:170-175
(7)Chan AO et al.  2007.  Increasing dietary fiber intake in terms of kiwifruit improves constipation in Chinese patients. World J Gastroenterol.  13(35):4771-5.
(8)Rish EC et al.  2002.  Kiwifruit promotes laxation in the elderly.  Asia Pacific Journal of Clinical Nutrition.  11(2):164.
(9)Cunnane, S. C., et al.  Nutritional attributes of traditional flaxseed in healthy young adults.  American Journal of Clinical Nutrition.  61(1):62-68, 1995.
(10)Dahl, W. J., et al.  Effects of flax fiber on laxation and glycemic response in healthy volunteers.  Journal of Medicinal Food.  8(4):508-511, 2005.
(11) Anti M et al.  1998.   Water supplementation enhances the effect of high-fiber diet on stool frequency and laxative consumption in adult patients with functional constipation.  Hepatogastroenterology.  45(21):727-32
(12) Arnauld MJ.  2003.  Mild dehydration: a risk factor of constipation?  Eur J Clin Nutr.  57(Supplement 2):S88-S95.
(13)Daher S et al.  2001.  Cow’s milk protein intolerance and chronic constipation in children.  Pediatr Allergy Immunol.  12(6):339-42
(14)Iacono G et al.  Intolerance of cow’s milk and chronic constipation in children.  New England Journal of Medicine.  339(16):1100-1104, 1998.
(15)Heine RG et al.  2002.  Cow’s milk allergy in infancy.  Curr Opin Allergy Clin Immunol.  2(3):217-25


Written by Ani Kowal


Boosting immune health. Can ‘back to school’ coughs and colds be prevented?

Continuing with the theme of child health I have decided to look at the prevention of common infections such as those of the ear, nose and throat, and tummy upsets.  Children returning to school after the long holiday break will be exposed to others who they may not have seen in weeks and also to the various ‘bugs’ that they may be carrying.  Fear not, it is not inevitable that your children will end up feeling poorly and catching every illness around them! 

A healthy, strong immune system will help to prevent various infections, or keep them short and less intense if they do occur.  Ensuring that your child is eating healthily will mean that they are getting all the vitamins, minerals and essential fatty acids they need in order to keep their immune system fighting fit.  However, I am aware that many children are not regularly getting the recommended daily 5 portions of fruit and vegetables.  This may mean that they are lacking in essential nutrients and their immune system may not be running at optimum.  Certain supplements, specially formulated for children, may be helpful in supporting a healthy diet in order to keep the immune system healthy.  However, a supplement cannot be seen as a replacement for the foundations provided by a healthy lifestyle.

Here I will be looking at some of the evidence which suggests that a multivitamin and mineral supplement taken together with a fish oil supplement (to provide essential omega 3 fatty acids) and a pre/pro-biotic supplement could be useful in helping to prevent childhood infections. 

Two papers have been published by a group of researchers who used a fish oil and multivitamin-mineral supplement in children who regularly suffered from recurrent ear(1) and sinus(2) infections.  The studies were very small and preliminary but both suggested benefit in the prevention of these common childhood conditions.  The researchers suggest that such preventative treatments could reduce the need for prescribed antibiotics.  Evidence also exists to suggest that individuals who suffer from recurrent tonsillitis infections may have a disturbed balance of various vitamins(3,4) and minerals(5), especially lowered zinc levels.

Previously I have written about zinc and vitamin C in relation to the prevention and shortening of the common cold and I would recommend you visit this post for more information. 

A few months ago I wrote about the importance of maintaining a good balance of ‘friendly’ bacteria in the digestive system in order to boost immune function and how evidence suggests that taking a daily probiotic supplement may prevent the occurrence of the common cold.  Children who have suffered from recurrent infections will normally have been exposed to frequent courses of antibiotics.  Antibiotics may indeed have been useful for fighting the bacterial infection, however they also kill many of the beneficial bacteria that would normally live in a healthy gut.  This imbalance could lead to a less efficient immune system and an increased likelihood of further infections.  One study(6) revealed that; in children with acute infections of the upper and lower respiratory tract, such as bronchitis and pneumonia, a probiotic supplement seemed helpful in regulating the immune system.  A recent review paper(7) indicated that probiotics also have immune enhancing effects in children and may prevent infections and diarrhoea. 

A daily supplement containing probiotics and prebiotics (such as FOS fructooligosaccharides) may be worth considering.  For more information on prebiotics and probiotics I would suggest visiting the post on irritable bowel syndrome which defines and explains these supplements.

When considering multi-nutrient supplements I would suggest a child-specific ‘food-state’ supplement as these will be easily absorbed by the body.  Again I would like to stress that supplements should not be seen as a substitute for a healthy, balanced diet plentiful in a variety of colourful fruits, vegetables and healthy fats. 

Best wishes to all children for an enjoyable first term back at school!

(1)Linday LA, Dolitsky JN, Shindledecker RD, Pippenger CE. 2002.  Lemon-flavored cod liver oil and a multivitamin-mineral supplement for the secondary prevention of otitis media in young children: pilot research. Ann Otol Rhinol Laryngol.  111(7 Pt 1):642-52.
(2)Linday LA, Dolitsky JN, Shindledecker RD.  2004.  Nutritional supplements as adjunctive therapy for children with chronic/recurrent sinusitis: pilot research. Int J Pediatr Otorhinolaryngol.  68(6):785-93.
(3)Aleszczyk J et al.  2001.  [Evaluation of vitamin and immune status of patients with chronic palatal tonsillitis][Polish Article].  Otolaryngol Pol.  55:65-67
(4)Shukla GK et al.  1998.  Comparative status of oxidative damage and antioxidant enzymes in chronic tonsillitis patients.  Boll Chim Farm.  137:206-209
(5)Onerci M et al.  1997.  Trace elements in children whith chronic and recurrent tonsillitis.  Int J Pediatr Otorhinolaryngol.  41:47-51
(6)Lykova EA, Vorob’ev AA, Bokovoi AG, Murashova AO.  2001.  [Impaired interferon status in children with acute respiratory infection and its correction with bifidumbacterin-forte] [Article in Russian].  Zh Mikrobiol Epidemiol Immunobiol.   Mar-Apr;(2):65-7 
(7)Nova E, Wärnberg J, Gómez-Martínez S, Díaz LE, Romeo J, Marcos A. Immunomodulatory effects of probiotics in different stages of life. Br J Nutr. 2007 Oct;98 Suppl 1:S90-5.

Written by Ani Kowal


Get a good gut feeling about digestive health – Irritable Bowel Syndrome (IBS) Part I

Two review papers(1,2) have recently been published in the journal ‘Nutrition in Clinical Practice’ which look at the therapeutic approaches to dealing with irritable bowel syndrome (IBS).  They cover everything from cognitive behaviour therapy and hypnosis to diet and nutrition.  The papers are timely, this is a topic I am often asked about and have decided to spend the next few posts covering various nutritional aspects of IBS.

IBS describes a combination of symptoms including constipation, diarrhoea, abdominal pain/discomfort, nausea and vomiting, feelings of fullness, gas and bloating.  Sufferers are often embarrassed by the condition which generally develops in individuals between the ages of 20 and 30 and affects around 20% of the population.  IBS also appears to be more common in women than men.

Get a Gut feeling about Digestive Health
Get a Gut feeling about Digestive Health - The bacteria in the digestive system of individuals suffering from IBS seems to be different to healthy people with fewer ‘beneficial/friendly’ bacteria such as Bifidobacteria and Lactobacilli being present in those with IBS

The causes of this uncomfortable condition are unclear.  However, an imbalance in intestinal bacteria is frequently implicated.  Often IBS develops after a bout of gasteroenteritis or repeat courses of antibiotics (which kill off the vast majority of intestinal bacteria).  The bacteria in the digestive system of individuals suffering from IBS seems to be different to healthy people with fewer ‘beneficial/friendly’ bacteria such as Bifidobacteria and Lactobacilli being present in those with IBS.

Up to about 30 years ago it was a common misperception that the major functions of the large intestine (colon) was simply water re-absorption and storage of waste matter.  The colon is now recognised as an important organ due to the number of bacteria present (well over 10million bacteria are present in the colon per g of contents!).  These bacteria produce compounds, which can have beneficial/positive, neutral or damaging influences on the body.  Age, stress, antibiotics, the environment and diet can all affect the type of bacteria present in our digestive system.  A healthy diet may help boost the number of the friendly bacteria and hence decrease the incidence of infective disorders of the gastrointestinal tract and boost natural resistance against them.

The knowledge that specific species of bacteria may be of benefit to our health, especially Lactobacilli and Bifidobacteria, led to the development of probiotics, prebiotics and synbiotics which are designed to beneficially alter the bacteria present in our gut.  Most people will have a predominance of Bacteriodes bacteria in their digestive systems, these have both pathological and neutral effects.  For optimal health it would be better for us to have a gut dominated by Bifidobacteria and Lactobacilli.  The health promoting effects of these bacteria include prevention of the growth of harmful bacteria, improvement of immune functions, reducing gas/bloating problems, improved digestion and better absorption of essential nutrients and vitamin synthesis.  A probiotic, prebiotic or symbiotic supplement may be a way of beneficially altering the bacterial status of our colon.

A probiotic is a supplement containing live friendly bacteria which aim to improve intestinal bacteria balance.  Probiotics are available as yoghurts, fermented milks, fortified fruit juices and freeze dried capsules/powders.

A prebiotic is a food that stimulates the growth of the beneficial bacteria already present in the colon.  Fructooligosaccharides (FOS) which can be bought as powders are the most common prebiotics available.  Natural prebiotics can be found in asparagus, onion, chicory and garlic.

Synbiotics are a mixture of probiotics and prebiotics.

Tomorrow I will look further into these supplements and their use in the alleviation of IBS specific symptoms.



(1)Wald A & Rakel D.  2008.  Behavioural and complementary approaches for the treatment of irritable bowel syndrome.  Nutrition in Clinical Practice.  23:284-292
(2)Heitkemper MM & Jarrett ME.  2008.  Update on irritable bowel syndrome and gender differences.  Nutrition in Clinical Practice.  23:275-283


Written by Ani Kowal



Can dietary change help asthmatics to breathe easier? Part II

At the beginning of the week I examined how a Mediterranean diet may be useful in the prevention and easing of asthma symptoms.  Today I wanted to add a little more information on the link between diet and asthma.

Salt consumption has been linked to asthma.  A review(1) of studies found that reducing salt intake may be helpful in reducing the severity of asthma attacks in affected individuals.  One study found that giving salt, an additional 6.1g per day, worsened symptoms in asthmatic patients and increased their use of inhaled steroids.  The authors of this study suggest that a low salt diet (around 5g per day) may have favourable effects in patients with asthma and can reduce the need for anti-asthma drugs(2).  Salt appears to heighten the airways’ response to histamine causing increased airway constriction(3).  Avoiding the addition of salt to food and limiting consumption of processed foods might help to reduce asthma symptoms and is also a good idea for all of us.  Excess salt has been linked to various conditions including high blood pressure, heart disease, cancer, kidney problems, osteoporosis and fluid retention (for more information on salt and health visit Consensus Action on Salt and Health CASH).

Interesting evidence shows that the gut bacteria of healthy infants appears different to those who suffer from allergies, eczema and asthma (known as ‘atopic’ infants).  Atopic infants seem to have a disturbed balance between beneficial and potentially harmful bacteria in their large intestine(4,5,6).  A healthy balance of microorganisms in the digestive system is thought to be essential for the normal development and maturation of the immune system.  In one study, the probiotic Lactobacillus GG was give to pregnant women who had at least one first-degree relative (or partner) with an allergic condition such as atopic eczema, allergic rhinitis, or asthma.  After the birth, the probiotic was also given to the child for 6 months.  Probiotic supplementation significantly reduced risk of early allergic disease in children at high risk (7)

Research in this area is still in the early stages, clinical studies of children and supplement studies in animals do suggest that the exposure to microbes through the digestive system powerfully shapes immune function.  Taking a probiotic or prebiotic supplement during pregnancy, breastfeeding and early childhood could be considered in order to prevent against asthma/allergy development in children.  Some infant milks are already including pre probiotics in their formulation (Always check with a doctor before undergoing any supplementation programme, especially during pregnancy).

Finally I would like to mention food allergies.  If your child suffers from asthma it may be worth taking them to the doctor for a skin-prick test in order to determine whether they suffer from a true food allergy.

Food sensitivity may be an underlying factor in asthma, especially in childhood asthma.  In one study, 91% of children with respiratory allergy improved on a six-week diet that excluded common problem foods including grains and dairy products(8).  And a review(9) found that approximately 5% to 8% of asthma patients have a food allergy that can be confirmed via a food challenge. Identification and elimination of problem foods is often a useful strategy in the management of asthma.  This should always be done under the supervision of a doctor. 

(1)Mickleborough TD & Fogarty A. 2006. Dietary sodium intake and asthma: an epidemiological and clinical review.  International Journal of Clinical Practice.  60:1616-1624.
(2)Medici TC et al.  1993.  Are asthmatics salt-sensitive? A preliminary controlled study. Chest.  Oct;104(4):1138-43
(3)Burney PG et al.  1981.  The effect of changing dietary sodium on the bronchial response to histamine.  Thorax.  44(1):36-41
(4)Kirjavainen PV et al.  2001.  characterizing the composition of intestinal microflora as a prospective treatment target in infant allergic disease.  FEMS Immunol Med Microbiol.  32:1-7. 
(5)Kirjvainen PV et al.  2002.  Aberrant composition of gut microbiota of allergic infants: a target of bifidobcterial therapy at weaning.  Gut.  51:51-55. 
(6)Murch, SH.  2001.  Toll of allergy reduced by probiotics.  Lancet.  357:1057-1059
(7)Kalliomaki M et al.  2001.  Probiotics in primary prevention of atopic disease: a randomised placebo-controlled trial.  Lancet.  357:1076-1079
(8)Ogle KA & Bullock JD.  1980.  Children with allergic rhinitis and/or bronchial asthma treated with elimination diet: a five-year follow-up.  Ann Allergy.  May;44(5):273
(9)Miller A.  2001.  The etiologies, pathophysiology, and alternative/complementary treatment of asthma.  Alternative Medicine Review.  6(1):20-47.

Written by Ani Kowal


Studies show that good bacteria in the gut do more than just protect our digestive systems

Whilst writing my last post about zinc and the common cold I came across some interesting research and evidence about probiotics and how they may be useful in enhancing the function of our immune system.  Probiotics are supplements containing ‘beneficial’ or friendly bacteria which inhabit the intestines.  These friendly bacteria produce various substances in our bodies, such as acetic acid, lactic acid and hydrogen peroxide, which  may help to counteract detrimental bacterial and viral infections in all parts of the body (not just in our digestive systems). 

Two studies (1,2) have looked specifically at how taking probiotics daily can prevent us from catching colds and how they may affect the duration and severity of cold symptoms if we do succumb.  Results suggest that taking probiotic supplements for at least three months had a positive effect on the cells of the immune system, shortened common cold episodes by almost 2 days and reduced the severity of symptoms!

Evidence for the various health benefits of taking daily probiotic and/or prebiotic supplements is growing each year.  Probiotics work by supplying ‘beneficial/friendly’ bacteria to the digestive system and Prebiotics, often called FOS or fructooligosaccharides, work by promoting the continued growth of friendly bacteria present in the intestines.  FOS act as a food source that only the beneficial bacteria can use to grow.  Personally I have taken prebiotics for many years now.  One of my professors at university, Prof Glen Gibson, has published several scientific papers and studies concerning the benefits of prebiotics and probiotics to health and he spurred me into taking a daily supplement. 

Many products are available that combine Probiotics and Prebiotics together.  After a month of taking the combined supplement you may wish to switch and use a prebiotic/FOS supplement only.  This will help to maintain high levels of the beneficial bacteria in the digestive system.
(1) de Vrese M et al.  2005.  Effect of Lactobacillus gasseri PA 16/8, Bifidobacterium longum SP 07/3, B. bifidum MF 20/5 on common cold episodes:  a double blind, randomized, controlled trial.  Clinical Nutrition.  24(4):481-491
(2) Tubelius, P et al.  2005.  Increasing work-place healthiness with the probiotic Lactobacillus reuteri:  a randomised, double-blind placebo-controlled study.  Environ Health.  4(1):25

Written by Ani Kowal