Before diving into the specifics, we want to start with the basics of bacteria names. When you see a reference to ‘genus’, this refers to the first segment of the name (e.g. ‘Lactobacillus’, ‘Bifidobacterium’). The ‘species’ follows the genus (e.g. ‘acidophilus’, ‘lactis’). Got it? Okay! Let’s continue…
Bifidobacterium and Lactobacillus bacteria feed off sugar, fermenting it and turning it into lactic acid. You may be aware that lactic acid is what causes the burning feeling in your muscles during intense exercise. In a situation where your muscles run out of oxygen, the only way to convert sugars into energy for your workout is fermentation, producing lactic acid. While lactic acid is not good for your muscles, the lactic acid produced by probiotics is actually good for your gut. Its acidity creates an inhospitable environment for the bad microbes and inhibits their growth. This can give you greater immunity and protect you against various illnesses.
The differentiating factor between Lactobacillus and Bifidobacterium compared to other bacteria is their ability to ferment carbohydrates into short chain fatty acids (SCFAs). SCFAs are the main source of energy for the cells lining your intestine. As acids, their low pH adds to the protective environment and can also boost mineral absorption, such as calcium for healthy bones.
If you are on the market for a probiotic to manage irritable bowel syndrome (IBS) or constipation, Bifidobacterium seems to be the genus you want to look for according to research findings. B. lactis in particular has been shown to provide significant relief from constipation. L. acidophilus appears to reduce the severity of inflammatory bowel disease (IBD) by decreasing inflammatory factors.
Both strains may also be helpful following a course of antibiotics as these disrupt both bad and good bacteria. It is important to replenish your gut with some probiotics to reduce the risk of antibiotic-associated diarrhoea.
Warning: If you have a history of health issues such as a weakened immune system, seek advice from your GP before taking probiotics.