Add as bookmark

Encouraging Healthy Inhabitants in the Gut

by Penny Crowther(more info)

listed in colon health, originally published in issue 191 - February 2012

Over the last 10-15 years, probiotics have undergone something of an image transformation. Not so long ago most medics considered them to be a quack remedy on a par with snake oil, with no proof of efficacy. Fast forward to 2012, hundreds of scientific studies later and probiotics are now being recommended by gastroenterologists and on national TV (Channel 4 The Food Hospital) as part of an effective treatment for IBS-induced hair loss.

Probiotic is a Greek word which means "for life". The health benefits of cultured and fermented foods have a long history dating back to ancient civilizations. It wasn't until the early nineteenth century however, that a culture of Streptococcus Thermophilus and Lactobacillus bulgaricus was officially developed by Metchnikoff, the head of the Pasteur Institute in Paris, who proposed it as a tonic for the bowel.

In addition to specific immune related functions, some of the researched effects of probiotics are:

  • Synthesis and absorption of B vitamins[1] including B3, B6, biotic and folic acid;.
  • Synthesis of vitamin K;
  • Recycling of oestrogen involved in female hormone imbalance;
  • Manufacture of lactase,[2] the enzyme that digests lactose in dairy products.
  • Absorption of minerals, particularly iron and calcium. This is good reason to take a probiotic when supplementing minerals;
  • Relief of constipation by helping to form soft, bulky and well lubricated stools which pass through the colon swiftly. A four week Canadian study in which probiotics were given to 70 people with chronic constipation found that 89% reported an improvement in symptoms;[3]
  • Binding of cholesterol in the gut, to lower excess levels;[4]
  • Prevention of travel bugs. A study by Professor Glenn Gibson, head of microbiology at Reading University showed that taking probiotics for five days before and during travel abroad resulted in a 30 percent reduced likelihood of picking up bugs.[5]
  • Supportive of healthy digestive function;
  • Management of inflammation;
  • Prevention/treatment of atopy in children;[6,7]
  • Production of antimicrobial substances which destroy yeasts and bacteria. Some species produce anti-tumour substances;
  • Detoxification of harmful substances;
  • A recent review  discusses the link between obesity and changes in the composition and metabolic function of gut microbiota/ There is evidence to show that different strains of bacteria are found in the guts of overweight people compared to lean people.  Gut microbes change according to the type of diet eaten and certain types (which can be passed from one generation to another) will affect the physiology of the host and influence weight gain.  

Barrier Defences
At a recent lecture organized by the Natura Foundation, I was reminded about the importance of flora, not only in the gut, but on other body barriers such as the skin, lungs, eyes, ears, nose and throat. These are the first line of defence against the external environment and healthy flora should form a thick protective layer over the barriers.  This means infection causing pathogens cannot gain entry and activate the immune system. Allergies and intolerances are also less likely to occur.

Causes and Effects of Imbalanced Bacteria
A certain amount of unhealthy gut bacteria is a given but the ratio between good and bad is what is important. If the good bacteria are found in large enough quantities in the human gut, the undesirable, disease causing bacteria will be kept in check.[8] A balance favouring the unhealthy bacteria is known as dysbiosis. Dysbiosis is a factor in many common conditions, including, for example, rheumatoid arthritis, allergy, IBS, diabetes, obesity and chronic fatigue syndrome.

Smoking, unhealthy food choices, medications and environmental pollution all negatively affect bacterial balance.  Of the medications, antibiotics, steroids (e.g. cortisone, ACTH, prednisolone, the Pill, HRT) are particularly destructive to the bowel flora. Chemotherapy will mean intensive probiotic therapy is needed.

Stress will interfere with barrier repair because it alters the pH in favour of a medium which encourages unhealthy bacteria. Stress also stimulates enzymes that eat away at the gut lining.

The best way to assess the state of the flora is to check the stools! A healthy stool should be cylindrical in shape, not at all sticky, break up easily when flushed and have no odour. If this is not the case, your bowel flora probably need improving. A diet rich in vegetables and soluble fibre (oats, wholegrain rice, spelt, rye bread) will help. However grains do not suit some people's digestive systems and IBS sufferers cannot tolerate too much fibre. A probiotic supplement can be useful.

Probiotic Supplements
Choose a probiotic that is effective i.e. contains a high number of bacteria and proven strains that are resistant to stomach acid and will adhere to the intestinal wall. A capsule or powder is generally preferable to a yoghurt drink which often has sugar added. The species of probiotic is, for example Lactobacillus acidophilus or Bifidobacterium lactis and there are lots of different strains within the species, for example L. acidophilus DDS-1. This means that two acidophilus supplements will be different.

When to take Probiotics
The ideal time to take probiotics is on an empty stomach at least half an hour before breakfast or in the evening before bed, at least 2 hours after food.

The consensus amongst probiotic specialists is that it is worth taking a probiotic concurrently with a course of antibiotics and continuing the probiotic for a few weeks afterwards, rather than waiting until the antibiotics are finished before starting the probiotics. A gap of a few hours should be left between the probiotic and antibiotic when they are being taken simultaneously.

1. Alm L et al. Effect of Fermentation on B Vitamin Content of Milk in Sweden. Journal of Dairy Sciences 65: 353-359. 1982.
2. Alm L, Journal of Dairy Sciences. 64(4): 509-514. 1981.
3. Koebnick C, Wagner I, Ising K, Stern U. Ernaehrungs-Umschau 48: 392-396. 2001.
4. Marteau PR. Probiotics in clinical conditions. Clinical Reviews in Allergy and Immunology
 22 (3):255-73. 2002.
5. Black FT et al. Prophylactic efficacy of Lactobacilli on travellers diarrhoea. Conference in international travel medicine 1, Zurich, Switzerland. Berlin. Springer 333-5. 1989.
6. Viljanen M et al. Probiotic effects on faecal inflammatory markers and on faecal IgA in food allergic atopic eczema/dermatitis syndrome infants. Pediatr Allergy Immunol 16(1): 65-71.
7. Kirjavainen PV et al. Aberrant composition of gut microbiota of allergic infants; a target of bifidobacterial therapy at weaning? Gut 51(1): 51-55. 2002.
8. Collado MC et al. The impact of probiotics on gut health. Curr Drug Metab. Jan;10 (1):68-78. 2009.


  1. No Article Comments available

Post Your Comments:

About Penny Crowther

Penny Crowther BANT CNHC qualified as a nutritional therapist in 1997 and has been in clinical practice ever since. She has seen several thousand clients over the years, at her practice in London and online. Penny now specializes in nutrition for women in their 40s and beyond, particularly around peri and post menopause. Mid Life for women can be a time when fluctuating hormones play havoc with your wellbeing. In the midst of all the publicity around HRT, it's easy to forget just how powerful diet and lifestyle changes can be when it comes to navigating the menopausal years.

Penny will guide and support you through specific changes to your diet, targeted to you specifically, in midlife. She provides practical, easy to follow menu plans with easy and delicious recipes. The food you eat affects every cell and system in your body. It optimizes how you look and feel, both mentally and physically.

To book an appointment view consultation options here >>

As well as being a regular columnist for Positive Health, Penny has written for Holland and Barrett, and contributed to articles for the Daily TelegraphThe Times Literary supplement, Pregnancy & Birth and Marie Claire. She has been featured in the Daily Express, Daily Mirror and on local radio.

Penny is a registered nutritional therapist with standards of training endorsed by BANT (British Association for Applied Nutrition and Nutritional Therapy) and CNHC. This includes completing 30 hours of continuing professional development, annually.

Penny’s approach to health is holistic, and takes into account emotional, mental and environmental factors as well as nutrition. She has trained in coaching and studied many complementary therapies before qualifying as a nutritionist, which provides a broad foundation of knowledge in her nutrition practice. Penny may be contacted on Tel: 07761 768 754;

  • College of Ayurveda UK

    Diploma in Āyurvedic Medicine, 4-year self-paced distant learning program in Āyurvedic medicine.

  • June Sayer Homeopathy

    Training Academy Homeopathy Nutrition Reiki, Distant Learning. Diet, Health Screening, Detox, Stress

  • Water for Health

    Specialist online health store focused on hydration, body pH balance and quality nutrition.

  • Beginner's Guide to ME

    Essential reading for people/carers with ME/CFS serious debilitating illness. Counteracts bad advice

  • Liposomal Nutrients

    Optimum system for nutrient delivery to cells - fully bioavailable vitamins absorbed and metabolised

  • Seaweed as Superfood

    Comprehensive nutrient balance found in no other natural food but seaweed: colon health, weight loss

  • Super Patch Wellbeing

    Super Patches – a most revolutionary advance in wellbeing strategies in the history of medicine

  • mycology research MRL

    MRL markets mushroom products food grade US & Netherlands GMP standards. Health Professional Videos

  • Ultimate Body Detox

    Immune system support & heavy metal detox - 3 powerful products: ACS 200, ACZ Nano & ACG Glutathione

  • nutrition and cancer

    by Sandra Goodman PhD The latest scientific research regarding Nutrition and Cancer. Full details at

top of the page