Taking probiotics with a Big Mac might not do you any good at all, according to an article published by the Division of Immunology at Harvard Medical School. In fact, The Western diet, very low in dietary fiber, has shifted our gut microbiota to become less diverse than more traditional diets, which is wreaking havoc on our health and not providing an optimal environment for growing beneficial bacterial.
In this study, mice were fed a fiber-rich (FR) diet, a fiber-free (FF) diet and prebiotics (soluble glycans found in prebiotics). Some groups were fed alternately to mimic the human diet. Results showed that on the fiber-free diet, the numbers of two mucus-degrading bacterial species – Akkermansia muciniphila and Bacteroides caccae increased, whereas the grow of two fiber-metabolizing (and beneficial) species, Bacteroides ovatus and Eubacterium rectale, decreased. The mixed diet mice had a mucus layer of intermediate thickness. The prebiotics diet results were similar to a fiber-free diet, suggesting that eating foods containing prebiotics does not have the same beneficial effect as actually eating dietary fiber.
A Western diet yields an overgrowth of mucus-degrading bacteria combined with a thinner gut mucus wall. This only increases our vulnerability to pathogenic bacteria, which outcompete any attempt at supplementing with good bacteria, rendering probiotics useless and devoid of health benefits.
In summary, a host’s diet needs to support the survival and efficacy of probiotics. Therefore, before pondering the CFU count on the probiotic label, be sure the host’s diet is replete with a fiber-rich diet that promote the growth of the beneficial bacteria.