Incidence of methanogenic bacteria in a sigmoidoscopy population: an association of methanogenic bacteria and diverticulosis.

Abstract

SUMMARY This study determined the incidence and concentration of methane-producing bacteria in tap water enema samples of 130 individuals taken before sigmoidoscopy. The number of subjects classified in five major colonic groups were as follows: normal colon 36, diverticulosis 57, inflammatory bowel disease 11, colon polyps 34, and colon cancer 11. Some patients were placed in more than one category. Ninety four of the subjects or 72% had methanogenic bacteria ranging in concentration from 6 to about 3 x 1010/g dry weight of faeces.The predominant methanogen in all groups was Methanobrevibacter smithii. Chi-square analysis showed that the incidence of methanogens in concentrations of 107/g dry weight of faeces or greater in patients with diverticulosis (58%) was significantly greater than in normal patients (25%). High methanogen concentrations are associated with excretion of methane in the breath.Studies by Bond et all showed that methane in man is produced by bacteria in the colon and indicated that most methane production occurs in the left colon. Methane is not metabolised further in man. It was estimated' that 20% of that produced is excreted through the lungs and that the remainder is passed as flatus. Miller and Wolin2 3 showed that the predominant methane producing organism in humans is Methanobrevibacter smithii. It produces methane by using hydrogen to reduce carbon dioxide. This organism remains at about the same concentration in the faeces of individuals studied over a period of 10-13 months.4 Thirty to 61% of adults excrete methane in the breath. -9 Breath methane is established in individuals between the ages of two and 10.1 Unlike breath hydrogen, breath methane does not usually increase when methane producers are given a non-absorbed carbohydrate.' 1(0 Breath methane does, however, increase in producers with high endogenous methane production after they are given a large dose of a non-absorbed carbohydrate.6 r-1 12

Methane-producing human subjects have higher serum glucose levels during oral glucose challenge than non-methane producers: a pilot study of the effects of enteric methanogens on glycemic regulation

“…These anaerobic archaea utilize hydrogen and ammonia produced by other microbes as substrates for the generation of methane [12][13]15,32]. The predominant methanogen in the human gut is Methanobrevibacter smithii [17][18][19]32], and there is increasing evidence for a specific role for M. smithii in the development of obesity. Using a germ free animal model, introduction of a single Bacteroides species (B. thetaiotaomicron) and M. smithii was found to result in greater weight gain than the introduction of B. thetaiotaomicron alone [27].…”

“…Once absorbed into the systemic circulation, methane is cleared via the lungs and can be quantitated by breath testing. The majority of methanogens colonizing the human gut are from the genus Methanobrevibacter; predominantly M. smithii [17][18][19]. While M. smithii is found in the isolated portion of the lower GI tract of 70% of unselected "normal" subjects, due to the threshold required for detection in the breath, only 15% of the population has methane on breath test (≥3ppm) [20,21], and we have previously shown that methane on breath test correlates with higher levels of M. smithii in stool [22].…”

Abundance and diversity of mucosa-associated hydrogenotrophic microbes in the healthy human colon

“…smithii is the predominant methanogen in the human colon (Miller et al, 1982;Weaver et al, 1986;Eckburg et al, 2005;Scanlan et al, 2008;Zhang et al, 2009). Msp.…”

Update on diagnostic value of breath test in gastrointestinal and liver diseases

“…Methane production is more disease specific as suggested by different studies, for example: Methane excretion is not found in diarrheal states such as ulcerative colitis or Crohn's disease and on the other hand it is more frequently observed in diverticulosis [22] and encoparesis [23] related with constipation.…”