chemotaxis refers to the ability of a microbe to
Chemotaxis Chemotaxis (from chemo- + taxis) is the movement of an organism in response to a chemical stimulus.[1] Somatic cells, bacteria, and other single-cell or multicellular organisms direct their movements according to certain chemicals in their environment. This is important for bacteria to find food (e.g., glucose) by swimming toward the highest concentration of food molecules, or to flee from poisons (e.g., phenol). In multicellular organisms, chemotaxis is critical to early development (e.g., movement of sperm towards the egg during fertilization) and subsequent phases of development (e.g., migration of neurons or lymphocytes) as well as in normal function. In addition, it has been recognized that mechanisms that allow chemotaxis in animals can be subverted during cancer metastasis.
Gut flora The small intestine contains a trace amount of microorganisms due to the proximity and influence of the stomach. Gram-positive cocci and rod-shaped bacteria are the predominant microorganisms found in the small intestine.[2] However, in the distal portion of the small intestine alkaline conditions support gram-negative bacteria of the Enterobacteriaceae.[2] The bacterial flora of the small intestine aid in a wide range of intestinal functions. The bacterial flora provide regulatory signals that enable the development and utility of the gut. Overgrowth of bacteria in the small intestine can lead to intestinal failure.[26] In addition the large intestine contains the largest bacterial ecosystem in the human body.[2] About 99% of the large intestine and feces flora are made up of obligate anaerobes such as Bacteroides and Bifidobacterium.[27] Factors that disrupt the microorganism population of the large intestine include antibiotics, stress, and parasites.[2]