肠道是人体的重要器官之一，它的主要作用就是帮助人体进行食物消化和营养吸收。同时他还有一个重要的功能就是守护人体健康，为我们提供一道重要的免疫屏障，而真正行使这些具体的功能不只是肠道本身，更多的是靠肠道内寄居的数量众多的微生物来完成的，这些微生物与肠道一起打造出一套肠道微生态系统，来共同完成，诸如免疫，营养供给等作用

在我们们肠道内众多的微生物群体可以大致分为三类，益生菌，中性菌以及致病菌，而足够量的益生菌是才是真正帮助我们维护健康的菌落，这个菌落成员众多，其中包括双歧杆菌属、乳杆菌属、肠球菌属和酵母菌属等。

益生菌在我们体内起到的主要作用包括一下几点：

1、维护肠道菌群平衡

 益生菌对肠道菌群的调节机制归纳起来主要有以下几个方面：

生物拮抗。益生菌就其种类而言，一般为肠道的优势菌群。在进入肠道以后，会迅速繁殖并且与其他有害生物竞争营养和所粘附的黏膜空间，同时也会主动分泌抗菌物质，如抗生素、过氧化氢等，造成其他有害生物生长受阻。

改变肠道pH值。益生菌在其生长过程中，大部分种类都会发酵产生乳酸，而这些乳酸能有效降低肠道pH值，从而抑制部分无法耐受酸性环境的有害微生物。

恢复肠黏膜。益生菌具有保护肠黏膜，减轻肠黏膜炎症以及辅助恢复肠黏膜的功能。

2、提高人体免疫力

   益生菌对免疫系统的调节机制较为复杂，但其核心在于可以刺激宿主的免疫应答，增强体液免疫及细胞免疫，从而增加机体免疫力。

益生菌在肠道疾病预防和治疗过程中应用比较广泛， 其中主要应用优先域包括以下几点：

1.应用于腹泻辅助治疗：

    腹泻根据其病因通常可分为肠道病原微生物或寄生虫感染、消化系统功能性或器质性疾病、代谢性疾病、自身免疫性疾病、放射性肠炎、抗生素导致肠道菌群紊乱等。但不论何种原因引起的腹泻，均不可避免地造成肠道菌群的严重紊乱。因此，临床上对于腹泻的治疗，益生菌已成为重要的辅助治疗手段，在恢复肠道菌群的平衡中起重要作用。

2.改善肠道微环境，调理便秘：

    便秘对于人体的伤害很大，是一件很痛苦的事，同时便秘患者由于粪便长时间在肠道里积累，还易诱发肠道腐败菌的繁殖而造成毒素的沉淀。现在治疗便秘的方法有很多，通常常用的做法包括服用泻药、促肠动力药、灌肠等，而根据新研究发现便秘患者肠道菌群与健康人群同样有着很大差别。这种菌群的差别也极有可能是造成人体便秘的一种原因。所以不管怎样，便秘患者在其他手段以外都要对于肠道菌群调节和恢复重视起来，而益生菌也确实可以帮助我们有效改善肠道微环境、维护肠道菌落平衡以及促进肠道蠕动。

3.炎症性肠病辅助治疗

     炎症性肠病是一类慢性肠道炎症性疾病，包括溃疡性结肠炎和克罗恩病等。主要症状有腹泻、腹痛和肠道不适。目前该病的发病机制通常认为与遗传因素、免疫因素、环境因素有关。因此，炎症性肠病的治疗时可以从调理肠道菌群、消除肠道炎症入手。目前，临床上多采用在传统治疗的基础上添加益生菌，将益生菌作为辅助治疗进行应用。

随着各界对于益生菌的功用的不断研究和开发，益生菌可应用优先域范围也在不断拓宽，包括目前我们认为比较棘手的肠道肿瘤，都与我们肠道内的菌群有着相应的关系，未来益生菌被应用于这类疾病的预防和治疗也是有着极大的可能，让我们共同期待益生菌的应用为我们开启新的健康之门。

Intestinal tract is one of the important organs of human body. Its main function is to help human body digest food and absorb nutrition. At the same time, it also has an important function to protect human health and provide us with an important immune barrier. The real exercise of these specific functions is not only the intestinal tract itself, but also depends on the large number of microorganisms living in the intestinal tract. Together with the intestinal tract, these microorganisms create a set of intestinal micro ecosystem to complete together, such as immunity and nutrition Supply and other functions

There are three kinds of microbial groups in our intestines: probiotics, neutral bacteria and pathogenic bacteria, and enough probiotics are the colonies that really help us maintain health. There are many members in this colony, including bifidobacteria, Lactobacillus, Enterococcus and yeast.

The main functions of probiotics in our body include the following:

1. Maintain the balance of intestinal flora

The regulatory mechanism of probiotics on intestinal flora can be summarized as follows:

Biological antagonism. Probiotics are generally the predominant flora in the intestine. After entering the intestinal tract, it will propagate rapidly and compete with other pests for nutrition and the mucosal space adhered to. At the same time, it will also actively secrete antibacterial substances, such as antibiotics, hydrogen peroxide, etc., which will hinder the growth of other pests.

Change intestinal pH. During the growth process of probiotics, most kinds of probiotics will ferment to produce lactic acid, which can effectively reduce the pH value of intestinal tract, thus inhibiting some harmful microorganisms unable to withstand the acid environment.

Repair intestinal mucosa. Probiotics have the functions of protecting intestinal mucosa, alleviating inflammation of intestinal mucosa and assisting in repairing intestinal mucosa.

2. Improve human immunity

The regulation mechanism of probiotics to the immune system is complex, but its core is to stimulate the host's immune response, enhance humoral and cellular immunity, and thus increase the body's immunity.

Probiotics are widely used in the prevention and treatment of intestinal diseases, including the following main application areas:

1 for the treatment of diarrhea:

Diarrhea can be divided into intestinal pathogenic microorganism or parasite infection, functional or organic diseases of digestive system, metabolic diseases, autoimmune diseases, radiation enteritis, and intestinal flora disorder caused by antibiotics. However, no matter what causes diarrhea, it will inevitably cause serious disorder of intestinal flora. Therefore, probiotics have become an important auxiliary treatment for diarrhea, and play an important role in restoring the balance of intestinal flora.

2. Improve intestinal microenvironment, regulate constipation:

Constipation does great harm to human body, which is a very painful thing. At the same time, due to the accumulation of feces in the intestinal tract for a long time, constipation patients are easy to induce the reproduction of intestinal spoilage bacteria, resulting in the deposition of toxins. Now there are many ways to treat constipation, including taking cathartic, enema, etc. according to the latest research, the intestinal flora of patients with constipation is also very different from that of healthy people. This kind of flora difference is also likely to be a cause of human constipation. In any case, the patients with constipation should pay attention to the regulation and recovery of intestinal flora in addition to other means, and probiotics can help us effectively improve the intestinal microenvironment, maintain the balance of intestinal flora and promote intestinal peristalsis.

Adjuvant treatment of inflammatory bowel disease

Inflammatory bowel disease is a kind of chronic intestinal inflammatory diseases, including ulcerative colitis and Crohn's disease. The main symptoms were diarrhea, abdominal pain and intestinal discomfort. At present, the pathogenesis of the disease is generally considered to be related to genetic factors, immune factors and environmental factors. Therefore, the treatment of inflammatory bowel disease can start from regulating intestinal flora and eliminating intestinal inflammation. At present, probiotics are usually added on the basis of traditional treatment, and probiotics are used as auxiliary treatment.

With the continuous research and development of probiotics from all walks of life, the scope of application of probiotics is also expanding, including the intestinal tumors that we think are more difficult at present, which have a corresponding relationship with the flora in our intestines. It is also possible for probiotics to be used in the prevention and treatment of such diseases in the future. Let's look forward to the application of probiotics Open a new door to our health.