List of Bacteria in Digestive Tract

Trying to put a number on the types of bacteria in our digestive tracts is a challenge. According to the website Types of Bacteria, there are approximately 300 to 1,000 individual species of bacteria living in your digestive system, with the number of living bacterial cells reaching over 100 trillion at any given time. While this may sound disturbing, the majority are not harmful in any way; many are helpful and serve important functions in our ability to properly digest food.

E. coli

• Escherichia coli (E. coli) bacteria live in the intestines of animals (primarily cattle) and people. Most strains of E. coli are harmless and help with digestion. We depend on E. coli for vitamin K and some of the B-complex vitamins; however, most associate E. coli with the strain 0157 : H7, which causes illness. Most cases of E. coli contamination come from undercooked beef or raw (unpasteurized) milk. Yet the infection can also be spread when food is contaminated with fecal bacteria. Symptoms of infection can appear one to eight days after contamination, and they usually include nausea, vomiting and diarrhea.

Bacteroides

• Bacteroides reside in the colon and are the most numerous of normal flora in that part of the digestive tract. They are involved in the utilization of nitrogenous substances, fermentation of carbohydrates, and biotransformation of bile acids and other steroids. Bacteroides are adapted to grow where there is no oxygen, and they pose no threat to us unless they get out of the colon and into the rest of our bodies. This can happen if there is an abscess, and this rare occurrence can be very dangerous as most bacteroides are resistant to many antibiotics.

Lactobacillus

• Lactobacillus acidophilus normally live in the digestive tract and are also present in some foods like yogurt, as well as in dietary supplements. Lactobacillus acidophilus is beneficial because it produces lactase, vitamin K and anti-microbial substances such as acidolphilin, acidolin, bacteriocin and lactocidin. It is used for treating and preventing diarrhea and is considered especially effective in treating diarrhea in children caused by the rotavirus. It is also considered to be possibly effective for managing irritable bowel syndrome symptoms, diarrhea in hospitalized adults and diarrhea caused by traveling.