Akkermansia muciniphila

Akkermansia muciniphila is a Gram-negative, non-motile, anaerobic, oval-shaped, and non-spore-forming bacteria.

In studies, A. muciniphila shows anti-inflammatory effects in humans and an inverse correlation between colonies of A. muciniphila and inflammatory conditions such as appendicitis or irritable bowel syndrome (IBS). Reduced levels of A. muciniphila are correlated with increased severity of appendicitis symptoms. An additional study revealed the intestinal tract of IBS patients have lower levels of A. muciniphila than patients without IBS.

Researchers have also revealed that Akkermansia muciniphila may be beneficial in treating obesity and type 2 diabetes. In one study, mice were overfed three times the fat content than lean counterparts. The obese mice were then fed their regular diet and supplemented with A. muciniphila, which encouraged the mice to lose over half their weight. An additional study published in mid-2015 indicated a correlation between the abundance of A. muciniphila, insulin sensitivity, and better metabolism in overweight or obese patients. Healthier patients have been observed to have higher levels of A. muciniphila as well as increased diversity. This study also revealed that higher levels of A. muciniphila were linked to weight loss. This bacteria often makes up 3 to 5 percent of the digestive tract, but has been observed in decreased numbers in patients with obesity. Researchers hypothesize that adding A. muciniphila increases the gastrointestinal tract wall thickness, which prevents food absorption.

Other additional research indicates that dietary fats may encourage A. muciniphila growth. Mice were fed identical diets varying only in fat: one set was given fish oil while the other received lard. Researchers observed increased levels of Akkermansia muciniphila, as well as the genus Lactobacillus (considered a probiotic), in the group that received fish oil in their diet. The group fed a lard diet showed dramatically reduced levels of A. muciniphila and Lactobacillus.

Fecal transplants were performed on these mice into a fresh batch, which had previously taken antibiotics that destroyed much of their gut microbiome. These new mice then consumed a lard-based diet. In spite of receiving identical diets, recipients of transplants from the lard-based diet mice revealed higher levels of Lactobacillus and inflammation; however, researchers observed increased A. muciniphila levels and reduced inflammation within the recipients of fish-oil based transplants. Scientists can conclude from this research that A. muciniphila may be associated to decreasing inflammation, and potentially a link between the human gut microbial communities, dietary fats, and dysbiosis.

References

Caesar, Rober, Tremaroli, V., Kovatcheva-Datchary, P., Cani, P.D., et al. Crosstalk between Gut Microbiota and Dietary Lipids Aggravates WAT Inflammation through TLR Signaling. Cell Metabolism. 2015. 22: 658–668. doi:10.1016/j.cmet.2015.07.026.

Derrien, M. (2004). "Akkermansia muciniphila gen. nov., sp. nov., a human intestinal mucin-degrading bacterium". International Journal of Systematic and Evolutionary Microbiology 54 (5): 1469–1476. doi:10.1099/ijs.0.02873-0. ISSN 1466-5026.

Van Passel, Mark W. J., Kant, R., Zoetendal, E.G. et al. The Genome of Akkermansia Muciniphila, a Dedicated Intestinal Mucin Degrader, and Its Use in Exploring Intestinal Metagenomes. PLoS ONE 6.3. e16876. PMC. doi: 10.1371/journal.pone.0016876.