<P> The largest number exist in the gut flora , and a large number on the skin . The vast majority of the bacteria in the body are rendered harmless by the protective effects of the immune system , though many are beneficial particularly in the gut flora . However several species of bacteria are pathogenic and cause infectious diseases , including cholera , syphilis , anthrax , leprosy , and bubonic plague . The most common fatal bacterial diseases are respiratory infections , with tuberculosis alone killing about 2 million people per year , mostly in sub-Saharan Africa . In developed countries , antibiotics are used to treat bacterial infections and are also used in farming , making antibiotic resistance a growing problem . In industry , bacteria are important in sewage treatment and the breakdown of oil spills , the production of cheese and yogurt through fermentation , and the recovery of gold , palladium , copper and other metals in the mining sector , as well as in biotechnology , and the manufacture of antibiotics and other chemicals . </P>
<P> The largest number exist in the gut flora , and a large number on the skin . The vast majority of the bacteria in the body are rendered harmless by the protective effects of the immune system , though many are beneficial particularly in the gut flora . However several species of bacteria are pathogenic and cause infectious diseases , including cholera , syphilis , anthrax , leprosy , and bubonic plague . The most common fatal bacterial diseases are respiratory infections , with tuberculosis alone killing about 2 million people per year , mostly in sub-Saharan Africa . In developed countries , antibiotics are used to treat bacterial infections and are also used in farming , making antibiotic resistance a growing problem . In industry , bacteria are important in sewage treatment and the breakdown of oil spills , the production of cheese and yogurt through fermentation , and the recovery of gold , palladium , copper and other metals in the mining sector , as well as in biotechnology , and the manufacture of antibiotics and other chemicals . </P>
where can you find bacteria that are not harmful
where can you find bacteria that are not harmful
the gut flora
the gut flora