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''Lactobacillus acidophilus'' (New Latin 'acid-loving milk-bacterium') is a species of gram positive bacteria in the genus ''Lactobacillus''. ''L. acidophilus'' is a homofermentative, microaerophilic species, fermenting sugars into lactic acid, and grows readily at rather low pH values (below pH 5.0) and has an optimum growth temperature of around . ''L. acidophilus'' occurs naturally in the human and animal gastrointestinal tract and mouth.〔(【引用サイトリンク】 publisher = European Bioinformatics Institute )〕 Some strains of ''L. acidophilus'' may be considered to have probiotic characteristics. These strains are commercially used in many dairy products, sometimes together with ''Streptococcus thermophilus'' and ''Lactobacillus delbrueckii subsp. bulgaricus'' in the production of acidophilus-type yogurt. Its genome has been sequenced. ==Health effects== Some strains of ''L. acidophilus'' have been studied extensively for health effects. The Mayo Clinic publishes a list of disorders for which ''L. acidophilus'' has been tested, grading the evidence for each use from strong evidence of effectiveness, through unclear, down to strong evidence of ineffectiveness.〔(【引用サイトリンク】 title=Mayo Clinic: Evidence - Lactobacillus acidophilus )〕 According to the list there is good (rather than strong) evidence supporting the use of ''L. acidophilus'' or yogurt enriched with it for the treatment of some vaginal infections; effectiveness for other conditions ranges from unclear to fair negative evidence. Some ''L. acidophilus'' strains may be able to survive gastrointenstinal transit, being resistant to bile, low pH, and digestive enzymes. They may then be able to adhere to human epithelial cell lines and human intestinal mucus.〔〔 A blend of bacterial strains including ''L. acidophilus NCFM'' decreased the incidence of pediatric diarrhea. ''L. acidophilus'' led to a significant decrease in levels of toxic amines in the blood of dialysis patients with small bowel bacterial overgrowth. At adequate daily feeding levels, ''L. acidophilus'' may facilitate lactose digestion in lactose-intolerant subjects. A University of Nebraska study found that feed supplemented with ''L. acidophilus L1'' and fed to cattle resulted in a 61% reduction of ''Escherichia coli'' O157:H7.〔(【引用サイトリンク】title=Good bacteria look promising for reducing E. coli )〕 Research has indicated ''L. acidophilus'' may be helpful reducing serum cholesterol levels. Antibiotics taken orally will kill beneficial, as well as harmful, bacteria, including ''L. acidophilus''. After a therapy that includes antibiotics, patients are occasionally instructed to take an ''L. acidophilus'' treatment in order to recolonize the gastrointestinal tract.〔 To that effect, ''L. acidophilus'' is often sold in health stores in pill or powder form as a nutritional supplement, as well as being available in many yogurts. A part of the claims in favor of such treatment refer to attaining a better digestion thanks to a recovered normal intestinal flora. ''L. acidophilus'' LA-5 produces bacteriocin CH5 that is both antibacterial and inhibitory against certain yeasts and molds and is effective against both ''Salmonella typhimurium'' and ''Campylobacter jejuni''.〔 It has been shown to improve bowel regularity and has been shown to have a preventative effect against traveller's diarrhea, as well as antibiotic-related bowel issues.〔 Because of its relation to gut-associated lymphoid tissue (GALT), ''L. acidophilus'' LA-5 has been associated with positive effects on the immune system such as increased cytokine, phagocytic activity and antibody production, as well as phagocytosis of Salmonella, and ''L. acidophilus'' NCFM has even been shown to reduce incidence of symptoms of fever, cough and runny nose.〔 Anti-inflammatory effects have also been observed in people consuming ''L. acidophilus'' NCFM. Additionally ''L. acidophilus'' LA-5 has shown to inhibit growth of breast cancer cells, and positive effects on chemotherapy patients.〔 An improvement of lipid metabolism has also been linked to ''L. acidophilus'' LA-5.〔 Animal studies of NCFM have indicated that it reduces intestinal pain by inducing u-opioid and canabinoid receptors in the intestines (of animals), but this effect has not been sufficiently shown in humans yet.〔 ''L. acidophilus'' may produce vitamin K and lactase. Some strains may produce bacteriocins such as acidolin, acidophilin and lactocidin. A study published in the Journal of the American College of Nutrition reported that yogurt containing ''L. acidophilus'' L1 has the potential to reduce risk for coronary heart disease by 6–10% by reducing serum cholesterol concentration.〔(【引用サイトリンク】 title=Effect of Fermented Milk (Yogurt) Containing Lactobacillus acidophilus L1 on Serum Cholesterol in Hypercholesterolemic Humans )〕 The Mayo Clinic lists use of ''L. acidophilus'' for heart disease among those "based on tradition or scientific theories" that "often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven."〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Lactobacillus acidophilus」の詳細全文を読む スポンサード リンク
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