1. * * Basic Information**
-Lactobacillus acidophilus belongs to the genus Lactobacillus and is a Gram positive bacterium. It is rod-shaped and usually exists in the form of a single or short chain. Lactobacillus acidophilus is an anaerobic bacterium that grows well in anaerobic environments, but can also survive in microaerophilic environments.
2. * * Living environment and distribution**
-* * Natural environment * *: Lactobacillus acidophilus is widely distributed in nature and mainly exists in some acidic environments. For example, in fermented dairy products such as yogurt, it is one of the main fermenting bacteria. In addition, it can also survive in the intestines, oral cavity, and other parts of the human body and animals.
-Human gut environment: The human gut is an important habitat for Lactobacillus acidophilus. Under normal circumstances, it forms a complex microbiota in the intestine along with other gut microbiota. The temperature (about 37 ℃), pH value (generally around 5.5-7.0), and abundant nutrients in the intestine provide suitable conditions for the growth of Lactobacillus acidophilus.
3. * * Physiological functions**
-Regulating the balance of gut microbiota**
-Lactobacillus acidophilus can competitively inhibit the growth of harmful bacteria in the intestine. It adheres to the surface of the intestinal mucosa, occupying the adhesion sites of intestinal epithelial cells, thereby preventing the attachment and invasion of harmful bacteria such as Escherichia coli and Salmonella. For example, it can secrete some antibacterial substances, such as bacteriocins, which can specifically inhibit the growth and reproduction of harmful bacteria, thereby maintaining a balance between beneficial and harmful bacteria in the intestine.
-It can also produce organic acids such as lactic acid and lower the pH value in the intestine. A lower pH environment is not conducive to the survival of harmful bacteria, such as Clostridium perfringens, because these harmful bacteria are more sensitive to acidic environments, and Lactobacillus acidophilus itself can adapt to this acidic environment, further consolidating its dominant position in the intestine.
-Enhance intestinal barrier function**
-Lactobacillus acidophilus can promote the expression of tight junction proteins in intestinal epithelial cells. These tight junction proteins are like "glue" that tightly connect intestinal epithelial cells together, preventing harmful substances (such as bacteria, toxins, etc.) from entering the bloodstream through intercellular spaces, thereby enhancing the physical barrier function of the intestine.
-Meanwhile, it can also stimulate the development and function of the intestinal mucosal immune system. For example, it can induce immune cells in the intestine to produce some immunoglobulins (such as IgA), which can bind to pathogens in the intestine, prevent them from binding to intestinal epithelial cells, and enhance the immune barrier function of the intestine.
-* * Digestion and absorption of nutrients**
-Lactobacillus acidophilus can produce enzymes such as β - galactosidase, which can help the human body break down lactose. For some lactose intolerant individuals, consuming products containing Lactobacillus acidophilus (such as yogurt) can alleviate symptoms of lactose intolerance.
-It also participates in the metabolic processes of other nutrients. For example, it can break down some complex carbohydrates into short chain fatty acids (such as acetic acid, propionic acid, butyric acid, etc.), which can be absorbed and utilized by intestinal epithelial cells to provide energy for the human body and have many benefits for intestinal health, such as maintaining the integrity of intestinal mucosa and regulating intestinal peristalsis.
4. Benefits to Human Health**
-Digestive system health**
-Prevent and improve diarrhea or constipation. In terms of diarrhea, when the gut is infected with pathogens (such as rotavirus infection) or when antibiotic use causes dysbiosis of the gut microbiota, Lactobacillus acidophilus can help restore gut microbiota balance and alleviate diarrhea symptoms. For constipation, it can promote bowel movements by regulating intestinal peristalsis and improving the gut microbiota environment.
-Relieve gastrointestinal inflammation. It can alleviate intestinal inflammatory reactions, for example, in adjuvant therapy for inflammatory bowel diseases such as ulcerative colitis and Crohn's disease, Lactobacillus acidophilus may alleviate inflammatory symptoms by regulating the intestinal immune system and improving intestinal barrier function.
-Immune system health**
-Enhance the body's immune system. Lactobacillus acidophilus can activate the intestinal immune system, promote the maturation and function of immune cells. By regulating the balance of intestinal flora, it indirectly affects the systemic immune system, improves the human body's resistance to pathogens, and reduces the incidence of infectious diseases.
-* * Other potential benefits**
-May be beneficial for cardiovascular health. Some studies have found that the metabolites such as short chain fatty acids produced by Lactobacillus acidophilus may have certain effects on reducing blood lipids, blood pressure, etc., but their specific mechanisms and effects still need further research.
-For women's health, it may play a certain role in maintaining the balance of vaginal microbiota. The normal vaginal flora also includes lactobacilli, and mechanisms similar to lactobacilli may help prevent harmful bacteria from growing in the vagina and prevent diseases such as vaginitis.
5. * * Safety and application precautions**
-Safety: Lactobacillus acidophilus is generally considered safe. It is a common microbial community in the human gut and some fermented foods, and generally does not cause harm to the human body at normal intake doses. However, for some people with low immune function, such as cancer patients receiving chemotherapy and AIDS patients, care should be taken when using products containing Lactobacillus acidophilus, because there is a potential risk of infection (although this situation is very rare).
-* * Application precautions * *: Lactobacillus acidophilus is widely used in the production of fermented dairy products, probiotic preparations, etc. in the food industry. When storing products containing Lactobacillus acidophilus, it is important to follow the product instructions and store them refrigerated to ensure the activity of Lactobacillus acidophilus. When taking probiotic supplements, it is best to take them after meals and be careful to avoid taking them together with antibiotics, as antibiotics may kill Lactobacillus acidophilus. If antibiotics and probiotics need to be used simultaneously, it is recommended to take probiotics 2-3 hours after antibiotic use.
