Role of anaerobic bacteria in the metabolic welfare of the colonic mucosa in man.

Abstract

SUMMARY Suspensions of isolated epithelial cells (colonocytes) from the human colon were used to assess utilisation of respiratory fuels which are normally available to the colonic mucosa in vivo. Cells were prepared from operative specimens of the ascending colon (seven) and descending colon (seven). The fuels that were used were the short chain fatty acid n-butyrate, produced only by anaerobic bacteria in the colonic lumen, together with glucose and glutamine, normally present in the circulation. The percentage oxygen consumption attributable to n-butyrate, when this was the only substrate, was 7301 in the ascending colon and 750% in the descending colon. In the presence of 10 mM glucose these proportions changed to 59%0 and 72%. Aerobic glycolysis was observed in both the ascending and descending colon. Glucose oxidation accounted for 85% of the oxygen consumption in the ascending colon and 300/ in the descending colon. In the presence of 10 mM n-butyrate these proportions decreased to 41% in the ascending colon and 16% in the descending colon. Based on the assumption that events in the isolated colonocytes reflect utilization of fuels in vivo, the hypothesis is put forward that fatty acids of anaerobic bacteria are a major source of energy for the colonic mucosa, particularly of the distal colon.The mucosa of the small and of the large bowel depend upon respiratory fuels to maintain cellular turnover and function. Respiratory fuels can either be derived from the bowel lumen or from the circulation.' The preferred respiratory fuels of the mucosa in the small bowel are glutamine and ketone bodies rather than glucose which is poorly oxidised and largely converted to lactic acid2. This lactic acid may be reconverted to glucose in the liver and is a means of conserving glucose during glucose absorption.3The respiratory fuels used by the colonic epithelial cells (colonocytes) have not been studied. In this regard, anaerobic bacteria produce short-chain fatty acids (SCFAs), mainly acetate, propionate, and butyrate, which are water soluble and readily absorbed.4 By using a method to prepare isolated surface epithelial cells5 it was possible to show that over 80% of energy needs for the colonic mucosa in the rat were obtained from the absorbed fatty acid,

Vinegar dressing and cold storage of potatoes lowers postprandial glycaemic and insulinaemic responses in healthy subjects

“…Studies indicate that especially butyrate is formed during colonic fermentation of RS (Scheppach et al, 1988). Butyrate is considered to be an important substrate for the colonocytes (Roediger, 1980). Furthermore it is not only associated with benefits in relation to colonic health in general, but also with favourable symptoms in patients with ulcerative colitis (Brouns et al, 2002;Hallert et al, 2003).…”

Effect of Nitrate on Methane Production and Fermentation by Slurries of Human Faecal Bacteria

“…The effect of NO: on butyrate production may be important from the viewpoint of gastrointestinal physiology since it is a major fermentation product in the human large gut, and is the major energy yielding substrate for colonic epithelial cells (Roediger, 1980). Moreover, butyrate has been shown to promote differentiation of malignant colonocytes (Augeron & Laboisse, 1984), and in the rat its deficiency results in the onset of clinical and biochemical lesions characteristic of ulcerative colitis (Roediger & Nance, 1986).…”

Cell type‐ and promoter‐dependent modulation of the Wnt signaling pathway by sodium butyrate

“…The short-chain fatty acid sodium butyrate, a possible therapeutic differentiating agent, [23][24][25][26][27] has been linked to changes in gene expression, which lead to growth arrest, differentiation and/or apoptosis. 28 -36 Butyrate has been shown to stimulate these processes in a number of cell lines, including colonic carcinoma cells.…”