By Dr R. Adeel guest for GastroLife
Weight gain is attributable to a number of well-known causes which we are usually aware of. However, there is another very important over-looked factor which is called methane gas. This gas is produced in the gut by Archaea, a microorganism that can be found in the intestinal tract, to which, not all but a considerable number of people are prone to getting affected in terms of weight gain and abdominal discomfort, which we will be discussing in this article.
Our gut is full of millions and trillions of bacteria, called normal flora or healthy germs, which normally help in the digestion and absorption process. Among those, a few organisms, such as Archaea, have the capability of producing methane gas through a process known as methanogenesis. Most of us are naturally immune to this process, however, a few can have rapid production of methane in the colon, causing potential distressing signs and symptoms, such as constipation, bloating, and excessive gases, as well as weight gain.(Simpsons et al., 2020). Quite often, these symptoms tend to overlap with the signs and symptoms of Irritable Bowel Syndrome (IBS) and Small Intestinal Bacterial Overgrowth (SIBO). Therefore, diagnosing methane gas associated abdominal discomfort and excessive weight gain has become an essential element of this clinical issue.
So, how does methane cause weight gain?
There has been a ton of research in this regard. One of the well-researched phenomena elaborates that the presence of methane in the GI tract slows down gut transit, which in turn not only increases methane gas production (delayed transit time), but also excessive calories gets absorbed because the contents stay longer in the gut, that may result in weight gain. The transit time refers to the retention of food in the human gut for longer duration than the required period of time that is sometimes caused by the presence of methane in ileum and colon (Quigley et al., 2019). Also, methanogens, in prone people, help to digest fiber rich food which further accelerates calories absorption (Evans et al., 2019). Not only this, an eventual fermentation process of methane in the gut has also been linked to excessive calories absorption.
All these factors mentioned above, followed by over-digestion of fibre rich foods, play concomitant role leading to excessive weight gain and distressing abdominal symptoms. To quote this, another recent research reveals that obese people who had a positive methane breath test, also had a BMI which was, roughly, almost 7 points higher than their counterparts. (Basseri RJ et al. Gastroenterol Hepatol. 2012;8:22-28).
Understandably, an effected person eventually is on the verge of becoming obese, which further increases the risk of them having life-long debilitating diseases such as high blood pressure, diabetes and in severe cases, heart disease as well.
Experimental Approach
In the respect of studying the effect of methane gas produced by gut microbiota, one research paper has provided some useful findings from a study conducted on 792 human volunteers (Black et al., 2020). The study showed that the people having a specific sort of microbiota in their gut are more prone to developing obesity because such microbiota are involved in the production of methane gas, which in turn is thought to be one of the stimulation factors in causing the symptoms associated with Irritable Bowel Syndrome (IBS) and Small Intestinal Bacterial Overgrowth (SIBO), such as abdominal discomfort, bloating, or constipation. (Jiang et al., 2019).
Diagnostic Elements
To reach the diagnosis, methane/hydrogen breath test is performed to estimate the amount of methane production, which is done by checking the amount of both hydrogen and methane in the exhaled breath samples following the ingestion of a testing substrate. The measurement of >10ppm of methane is usually considered positive for IMO, or Intestinal Methanogen Overgrowth.
Curative measures
The phenomenon of methane associated weight gain has been a concern for the people suffering from this condition. Not only is weight gain is the issue, but other associated symptoms such as bloating, distension, flatulence, nausea, vomiting and constipation can cause unbearable situations for the sufferers. One should consult a GP/Consultant for any concerns. The slow transit time and metabolic rate can be enhanced by changing the diet routine, followed by adapting to a daily exercise routine. However, all these measures need an appropriate diagnosis that can only be possible through methane breath testing.
References:
Shah, A., Talley, N. J., Jones, M., Kendall, B. J., Koloski, N., Walker, M. M., … & Holtmann, G. J. (2020). Small intestinal bacterial overgrowth in irritable bowel syndrome: a systematic review and meta-analysis of case-control studies. American Journal of Gastroenterology, 115(2), 190-201.
Simpson, C. A., Mu, A., Haslam, N., Schwartz, O. S., & Simmons, J. G. (2020). Feeling down? A systematic review of the gut microbiota in anxiety/depression and irritable bowel syndrome. Journal of affective disorders, 266, 429-446.
Black, C. J., & Ford, A. C. (2020). Global burden of irritable bowel syndrome: trends, predictions and risk factors. Nature Reviews Gastroenterology & Hepatology, 17(8), 473-486.
Zhang, L., Loh, K. C., Sarvanantharajah, S., Tong, Y. W., Wang, C. H., & Dai, Y. (2019). Mesophilic and thermophilic anaerobic digestion of soybean curd residue for methane production: characterizing bacterial and methanogen communities and their correlations with organic loading rate and operating temperature. Bioresource technology, 288, 121597.
Zhang, W., Zhang, F., Li, Y. X., Jiang, Y., & Zeng, R. J. (2019). No difference in inhibition among free acids of acetate, propionate and butyrate on hydrogenotrophic methanogen of Methanobacterium formicicum. Bioresource technology, 294, 122237.
Evans, P. N., Boyd, J. A., Leu, A. O., Woodcroft, B. J., Parks, D. H., Hugenholtz, P., & Tyson, G. W. (2019). An evolving view of methane metabolism in the Archaea. Nature Reviews Microbiology, 17(4), 219-232.
Sogodogo, E., Fellag, M., Loukil, A., Nkamga, V. D., Michel, J., Dessi, P., … & Drancourt, M. (2019). Nine cases of methanogenic archaea in refractory sinusitis, an emerging clinical entity. Frontiers in public health, 7, 38.
Lyu, Z., Shao, N., Akinyemi, T., & Whitman, W. B. (2018). Methanogenesis. Current Biology, 28(13), R727-R732.
Quigley, E. M. (2019). The spectrum of small intestinal bacterial overgrowth (SIBO). Current gastroenterology reports, 21(1), 3.
Quigley, E. M., Murray, J. A., & Pimentel, M. (2020). AGA clinical practice update on small intestinal bacterial overgrowth: expert review. Gastroenterology, 159(4), 1526-1532.
