Posts Tagged ‘Diet’

Gut Microbiome – The Basics

Tuesday, March 26th, 2024

A technique using DNA analysis now enables the identification of more types of bacteria that reside in and on the human body. Interest in the organisms found in the gut, known as the microbiome, has exploded in two directions in recent years. Do they have a part in disease and is there a commercial opportunity? The microbiome appears extensively in research papers and in all types of media and ‘health products’. Suddenly, the microbiome might be responsible for many diseases and needs to be controlled. Why do we have the microbiome, where is it, what is it for and what does it do? Is not easy to find among the barrage of ideas and theories.

The caecum is the first part of the large intestine (colon). Its wall is reinforced by immune tissue from the appendix to along the ascending colon to isolate the microorganisms contained within which are known as the gut microbiome. These organisms are acquired from dietary substances and some will survive in the residues of digestion. This is their only source since birth. The liquid ‘chyme’ from digestion enters the caecum from the small intestine (ileum) via a one-way valve (ileocaecal valve). Any reflux here produces small intestine bacterial overload (SIBO). Symptoms of this are not well defined but pain and bloating and IBS are mentioned.

The other import into the caecum microbiome is from the appendix. This is not an evolutionary relic but a safe refuge for the production of live microorganisms to supply and maintain the microbiome if it is depleted. When the output is blocked appendicitis ensues. Being without an appendix appears to increase the risk of infection in diverticular disease.

The liver also uses the food digestion pathway to get rid of detoxification chemicals and those which cannot be passed via the kidneys and urine such as heavy metals and pigments from red blood corpuscles. Bile products from the liver are recycled by the microbiome and returned to the liver for reuse.

When this digestion and body waste enters the caecum it joins the residues of several previous meals and itself will be diluted by several following meals. Colon wall muscles produce mixing movements before slowly advancing the content to the drying phase in the colon and the recycling of water. Because of the slowing of flow in the microbiome, ‘transit time’ from mouth to anus is not related to a complete meal. Similarly, it can take time for the colon to get rid of a toxic organism or irritant.

The array of organisms in the microbiome vary within and between people and are dynamic. They will only be there if they have the right nutrients and conditions to survive. There is an intimate relationship between diet and foodstuffs, and the type of organisms needed to deal with their digestion residues. This system is successful at the extremes of carnivorous or vegetarian diets.

What constitutes an ‘unbalance’ or ‘dysbiosis’ of good and bad bacteria in the microbiome is a human concept, as is the opinion that the microbiome always needs more in number and variety of microorganisms to be effective and healthy. Consider an individual with a restricted diet due to illness found to have a limited range of organisms in their microbiome. This is not dysbiosis but is the microbiome responding to diet. Taking prebiotics, probiotics or fermented food is just changing the diet and too much might not be helpful. Researchers looking for a link between the microbiome and diseases need to consider the effect of the disease on diet. Also, the gut-brain axis is a two-way communication system and neurotransmitter faults in diseases and drugs can also affect colon movement.

There are examples in nature where a lesser species is employed in a symbiotic relationship to solve a problem the host cannot deal with themselves. Powerful enzymes from the pancreas are produced to digest proteins in food but need to be destroyed before they attack the host’s tissues. They cannot be reabsorbed. When a stoma is formed by bringing the end of the small intestine to the outside of the body, the microbiome is not used and the surrounding skin can be attacked by enzymes. A stoma further along the colon, past the microbiome, does not have this problem. Cystic fibrosis patients have to take enzymes to digest their food. Sometimes the microbiome cannot cope with the quantity of enzymes and the ascending colon can be damaged. Only one pancreatic enzyme, elastase, is found in faeces. This is not harmful and is in fact used to show that the pancreas is working.

The microbiome is an integral part of body processes and has self-regulating properties which can be disrupted by pathogenic organisms and antibiotics. The colon itself is controlled by its nerve and blood supply which can change its movements. Not all health problems are caused by the microbiome which is part of an efficient recycling and disposal system which has served mankind for millennia.

© Mary Griffiths 2024

Diverticular Disease: The Fibre Story

Thursday, September 14th, 2017

In the early part of the 20th century constipation was not generally related to any individual illness. The idealised achievement of daily defaecation meant constipation was common particularly in the elderly. Treatment was not free until the NHS came along and natural and herbal laxatives were well used medications. Diverticular disease (DD) became recognised more before WW11. The distinguishing symptoms were pain, fever and diarrhoea. A low residue diet was recommended to reduce diarrhoea and give the bowel rest. Serious pain sometimes resulted in surgery. Infection and inflammation (diverticulitis) were not always present but pieces of food and faeces were trapped in diverticula. Avoidance of coarse fruit and vegetables, seeds and pips was recommended.

Hospital diet sheet for diverticulitis 1961………”forbidden foods – all fried foods, pips and skins of fruits, pastry, suet puddings, coarse stalky vegetables, salads, onions and celery, chunky marmalade, jam with pips or skins, wholemeal or brown bread, coarse biscuits-Ryvita, digestive, Allbran, oatmeal, Weetabix, Shredded Wheat, fruitcake or scones, nuts, dried fruit.”

A significant change in diet started about 1970 when treatment for diverticular disease (DD) was suddenly reversed.

Hospital diet sheet for diverticulis 1982………..”you can eat a normal varied diet but include…… (all of the forbidden foods from 1961 except fried food)….SUPPLEMENT meals with 2 teaspoonfuls of unprocessed bran twice daily. EAT LESS white flour in any form and white and other sugars. DIETARY FIBRE ….by helping to restore normal function of the digestive tract, fibre can be useful in the treatment of constipation and diarrhoea”

  • Who persuaded health professionals that wheat bran was good for diarrhoea?
  • What was the evidence for this complete reversal of treatment?
  • Did anyone ask patients if this helped them?
  • Who was behind this change?


The Microbiome in Diverticular Disease

Thursday, November 10th, 2016

New techniques which identify individual species have lead to an explosion of research into the role of bacteria in the colon. The terms ‘microbiota’ (the bacteria) and ‘microbiome’ (the collection of bacteria) are widely used. Some researchers consider the microbiome as equivalent to a body organ. It is certainly a significant, integral and specific part of the digestive system in man and animals. In protein-eating humans the microbiome is in the caecum, the first bag-like part of the large intestine which receives the residues of digestion and has enzymes which degrade amino acids from proteins. In herbivores the microbiome is in an earlier part of the digestive system to deal with large quantities of plant material to extract maximum nutrients for its host with enzymes to synthesise amino acids (1). The microbiome in humans can have both beneficial and unhelpful effects. Its position in the human body and the role of an associated appendix had not been considered apart from the letter on this website (2). The appendix is no longer considered a vestigial organ (3), contains extremely variable bacteria (4) and may be involved in microbiome changes (5).

Differences in the bacteria present in the microbiome have been found in conditions  such as obesity, autoimmune diseases, autism and bowel disease including diverticular disease (DD). The microbiome and its surrounding immune system are linked (6).

  • Is the microbiome content a cause or an effect of a disease?
  • Is the presence of a specific organism significant?
  • Could the microbiome be changed to treat a disease?

These are the questions research is trying to answer. Bacteria will only survive and flourish if the conditions and nutrients are right for the species. There is great variation both between and within people, with age and even with geographical location. So far only diet appears to make a difference (1, 7). Does the microbiome match dietary residues and the disease affect diet? (more…)

Diet and Fibre: A Wind of Change

Sunday, March 3rd, 2013

The theory that diverticular disease (DD) was caused by insufficient fibre in the diet was proposed about 40 years ago. Many websites, books and health professional reviews still persist in the recommendation that dietary fibre levels should be increased up to 30g or more per day (1,2). Some still suggest the use of added wheat bran which was found to cause problems some time ago. A wind of change is blowing through DD from a new generation of researchers and editors not afraid to point out the lack of evidence and shortcomings of the fibre theory. For example, Peery et al. (3) found that a high fibre diet with increased frequency of bowel movement was associated with a greater prevalence of diverticulosis. Low levels of dietary fibre do not cause DD (4) and increased fibre levels do not prevent diverticulitis (5).

Extra fibre merely adds to the problem (more…)

Diverticulitis: a wind of change

Sunday, December 2nd, 2012

There have been many changes over the years in the approach to diverticular disease (DD), even in the names used. Diverticular disease is the overall name. The presence of the grape-like diverticula on the outside of the colon results in a diagnosis of diverticulosis. Diverticulitis occurs when there is infection and inflammation of the diverticula but is often used when there are any symptoms caused by the disease.

Diverticulosis can have episodes of diverticulitis or complicated diverticulitis when problems such as bleeding, abscess, fistula or blockage need surgical treatment. This is a simplistic explanation of what might happen in DD in decreasing numbers, so that only a small fraction of people with DD ever need surgery. Any progression in the disease can stop and revert to symptomless diverticulosis at any time, some people with diverticulosis do not even know that they have it.

There has been confusion over many years about the symptoms with DD. (more…)

Diverticular Disease: Updated Epidemiology

Thursday, May 3rd, 2012


“Ideas, like living organisms, have their natural history, growing from conception through a more or less tumultuous adolescence and reproductive maturity to an old age, when they act as a bar to further progress. During this time they become so modified that their origin is obscured” Sir Richard Doll (1)


Looking at the occurrence of a disease in time and place, and assessing what might have influenced changes, is known as the science of epidemiology. The theory, that diverticular disease (DD) was caused by low levels of fibre in the diet, has been prominent for about 40 years. This was based on the rarity of DD in Uganda compared with Western countries such as Great Britain or the USA. It was assumed that high levels of fibre in the Ugandan diet protected people from DD and that an increase in dietary fibre would prevent DD and its symptoms would be eliminated. This was a conclusion too far. It ignored the rarity of DD in people eating very little fibre (2,3) and that vegetarians can get DD (4,5). There is no evidence that a high fibre diet prevents DD. The theory is so entrenched that if DD appears in a country then it is assumed that its inhabitants have changed from their normal to a low fibre western diet. This is particularly incongruous when applied to right-sided DD in the caecum and ascending colon. Even the theory’s originators thought low fibre levels could not be relevant to this area (6)

Data from post-mortems, mortality statistics and surveys can provide information on the occurrence of DD, each aspect contributing to the overall picture. Song et al. (7) showed how colonoscopy findings, over time, could plot a rising prevalence of DD in Korea. Jun and Stollman in 2002 (8) collected results from research papers on the % of patients with DD in series of examinations by colonoscopy or barium enema Xray. They used these results to show that changes in the prevalence of DD varied greatly in time and between countries. Searching through later research reports mainly in the PubMed website gives this type of information for many more countries. (References to these sources are too numerous to include here). The results fall into 4 distinct patterns of when DD appeared and how numbers have changed over time until 2010. (more…)

A look at the fibre theory

Thursday, August 11th, 2011

Diet sheets, recipes and menus are frequently requested by people newly diagnosed with DD but there is great variation in which foods help or cause problems for different people. A strict diet is not needed other than one which has plenty of variety and fluids, and conforms to the healthy diet currently recommended for everyone. Anything which is found to cause problems should be avoided, or reduced in amount or frequency but not to the extent that diet becomes restricted. People have different tastes and food should be enjoyed.


DD patients, new and old, will find that many resources recommend a diet high in fibre, some to the extent that fibre needs to be doubled in quantity with the aid of wheat bran. The fibre and bran treatment for DD started about 1970 when some doctors working in Uganda (1) found no cases of DD and attributed this to the large amount of fibre in the diet. As Mr Hutchinson described in the last Incontact magazine, too much fibre can have its own adverse effects (very high incidence of sigmoid volvulus). Was this evidence from Uganda sufficient to conclude that a low fibre diet was the cause of DD and increasing dietary fibre, and bran in particular, would both prevent and treat DD? (more…)

Getting Personal With Diet

Friday, August 20th, 2010

When somebody is diagnosed with a disease, after months of symptoms and tests, they quite reasonably expect that a treatment is available for their condition. For example, inhalers for asthma, nitrates for angina, drugs to control Parkinson’s disease symptoms or vitamin C for scurvy. 30 years ago diverticular disease (DD), like scurvy, was considered a deficiency disease which could be prevented and treated by increasing the amount of fibre in the diet with wheat bran. Diet sheets and recipes were handed out and, with a few existing bowel drugs for symptoms, the disease was sorted out. Nothing could be done about the diverticula once they had been formed, so a high fibre diet was and often still is the treatment on offer.

     This is 2005, has anything changed since the 1970s? (more…)