Taylor's Notes

The gut flora are the microorganisms that normally live in the digestive tract and can perform a number of useful functions for their hosts.

In addition to acidophilus, bifidum or bifido (Bifidobacterium bifidum) is another probiotic that provides healthful bacteria for adults, and it's especially useful in preventing acute diarrhea in infants. These, together with L. reuteri and L. casei, help prevent travelers' diarrhea and can also help reseed good intestinal bacteria affected by diarrhea and especially by antibiotic consumption. They also secrete small amounts of vitamins [B.sub.12] and K. By fermenting dietary fiber, they produce acids that inhibit enzymes capable of converting food products to precarcinogens. Thus they may help to prevent cancer, though as yet there's no hard evidence.

It can exists in several different shapes, including short curved rods, club shaped rods, and bifurcated Y shaped rods (how Bifidobacterium got its name).  There are over 30 species of Bifidobacterium isolated so far.

Our knowledge of the benefits associated with the probiotic bacteria dates back to the beginning of the previous century when the Nobel Prize laureate, Elie Metchnikoff, made observations that human health and longevity are associated with the ingestion of lactic acid bacteria. While working at the Pasteur Institute in Paris, he developed the theory that the presence of lactic acid bacteria in the intestine can control infections caused by pathogenic microorganisms and can help to control toxin-producing bacteria. Metchnikoff developed and prescribed to his patients bacteriotherapy, i.e., the use of lactic acid bacteria in dietary regimens^1,2.

Another researcher involved in this field was Henry Tissier, also at the labora-tories of the Pasteur Institute. In 1900 he discovered Bifidobacteria in the feaces of healthy, breast-fed infants and was first researcher who started promo-ting their therapeutic properties. Tissier believed that when Bifidobacteria displace putrefactive bacteria in the intestines, the correct microbial balance is restored^1,2.

The term “probiotic” microorganisms, based on the Greek expression“ pro bios” meaning “for life”, was introduced at a later stage. The currently used definition of probiotics is as fol-lows: “Live microorganisms, indigenous to the human intestinal tract, which, when consumed in adequate amounts improve the intestinal microbial balance and positively affect the functioning of the human intestinal tract and general health”³.