Scientific understanding of probiotics: clarify 10 cognitive errors

1. Probiotics and gut microbiota (commonly known as gut microbiota) are hot research topics and hot topics in the world in recent years. In media reports, probiotics often have various health effects and can "treat a variety of diseases"; but there are also some media reports that "probiotics are useless" and even "probiotics are harmful". https://eu.echemi.com/ https://eu.echemi.com/ Contradictory information is not conducive to consumers' scientific cognition and reasonable choices. For this reason, Kexin Food and Nutrition Information Exchange Center cooperates with the Chinese Center for Disease Control and Nutrition, the Chinese Institute of Preventive Medicine, Food Hygiene Branch, and the Chinese Society of Preventive Medicine for health communication. Clubs and other professional organizations clarify and interpret the 10 cognitive errors of probiotics for consumers' reference. Myth 1: Probiotics = lactic acid bacteria Probiotics refer to a class of living microorganisms that when ingested in sufficient amounts can play a beneficial role on human health, such as regulating intestinal flora, promoting nutrient absorption, and regulating immunity [1-3]. Lactic acid bacteria generally refer to the general name of bacteria that can ferment sugar and mainly produce lactic acid. It is not a strict name for the classification of microorganisms. Probiotics are not equal to lactic acid bacteria. Probiotics contain many strains, most of which belong to Bifidobacterium and Lactobacillus in lactic acid bacteria, such as Lactobacillus acidophilus, Bifidobacterium animalis (Bifidobacterium Bifidobacterium breve, long Bifidobacterium, Bifidobacterium bifidum, Lactobacillus plantarum, Lactobacillus casei, Bifidobacterium adolescentis, Lactobacillus paracasei, Lactobacillus reuteri, etc. [1-3]. lactis), Lactobacillus rhamnosus, But not all lactic acid bacteria are probiotics, and some lactic acid bacteria may even be harmful to the human body. Only specific strains of lactic acid bacteria whose health effects have been scientifically verified can be called probiotics [2-3]. In addition, probiotics do not necessarily have to be lactic acid bacteria. Certain yeasts and bacillus with health effects can also be probiotics, such as B. baumannii and Bacillus coagulans [2-3]. Myth 2: Prebiotics = probiotics Prebiotics are not probiotics. Prebiotics refer to a class of substances that can be selectively used by intestinal microorganisms and produce certain health functions [3-4]. Common prebiotics include fructooligosaccharides, isomaltose oligosaccharides, inulin, galactooligosaccharides, oligosaccharides from breast milk, etc. [3-4]. Although prebiotics cannot be digested by the human body, it can promote the growth and reproduction of beneficial bacteria in the intestine to promote human health. Therefore, it is

2. usually better to use probiotics and prebiotics in a reasonable combination, such as oligofructose, oligomeric semi-oligosaccharides The combination of lactose, inulin and bifidobacteria can promote the proliferation and function of bifidobacteria [2-3]. Myth 3: Dead bacteria are also considered probiotics Metabolites and cellular components of dead bacteria may have certain health benefits, such as polysaccharides, short-chain fatty acids and other substances are all beneficial to health [5-8]. But most studies have shown that the effect of live probiotic bacteria is better than the corresponding dead bacteria [9-10]. However, according to the definition of the World Health Organization, probiotics should be live bacteria, dead bacteria are not probiotics [1]. When purchasing related products, you should pay attention to the label. If the words "sterilization type" or "after inactivation treatment" are marked, the product does not contain live bacteria and is not a probiotic product. Myth 4: Probiotics are harmful to health Probiotics must be approved by the relevant departments before they can be sold on the market. The approved probiotics are safe for most people, and there is no evidence that long-term consumption of probiotics has adverse reactions [11-12]. Consumers can use it as recommended in the product manual, but special groups such as immunodeficiency patients and critically ill patients should consult a doctor before use [13-14]. Myth 5: Probiotics are all the same The effects of probiotics are strain-specific [15-16], that is, the effects of different probiotic strains are different [1], and there are individual differences in the effects of probiotics on the host. Therefore, in order to facilitate consumers to make reasonable choices, relevant companies should accurately label the strain information and suitable people in the product information.

3. Consumers should choose according to the strain information, the claimed function and their own health status, and seek expert advice if necessary. Myth 6: The more viable bacteria, the better the probiotic effect The effect of probiotics is related to the dose. Ingesting a sufficient dose of probiotics can achieve the corresponding effect, but different strains have different doses for health effects [2-3]. For the same probiotic strain, within a certain range, the effect of high dose is better than that of low dose, but it is not that the higher the dose, the better. For different strains of probiotics, due to the different doses of health effects, it is not appropriate to measure the probiotic effect by comparing the number of viable bacteria [17], or clinical evidence should prevail. Myth 7: The more strains, the better the effect Judging from the current scientific evidence, different strains may produce a synergistic effect, but not all strain combinations have this effect [18]. Therefore, the types of strains contained in probiotic products are not necessarily related to their effects, and the optimization of various strains needs to be further studied. Myth 8: Regular consumption of probiotics will cause dependence Probiotics strains that have undergone strict scientific evaluation are safe for normal people [19-20], and normal consumption will not make the human body dependent. Probiotics are a type of living microorganisms. The supplemented probiotics and the human intestinal flora will help each other and benefit each other. At present, there is no research to prove that long-term consumption of probiotics will make the intestine lose its ability to reproduce beneficial bacteria, or make people dependent. Myth 9: The role of probiotics is ethnically different The role of probiotics does not vary with race. The main factors affecting human intestinal flora are diet [21-22] and environment [23]. There will be some differences in the composition of intestinal flora of people around the world, but the role of intestinal flora in human metabolism is not There will be significant differences due to factors such as race, age, etc. [24]. At present, there is no evidence that the effects of probiotics will be significantly different due to different races. Myth 10: Probiotics package for all diseases At present, most scientists believe that probiotics can regulate intestinal flora [25-27], promote digestion, absorption and metabolism of nutrients in the intestine [28-31], which is beneficial to human health.

4. Probiotics have been used clinically and have achieved good results, such as regulating immunity [32], preventing and reducing the risk and duration of diarrhea in children [33-39], improving constipation [37,38], reducing Symptoms of enteritis [35,36,40], improvement of allergies [41], and help weight control [42-43]. However, the probiotic function reported by some scientific articles is still in the stage of cell or animal experiments and has not been proven by high-level clinical evidence. At the same time, due to the effects of strain specificity and individual differences [44-48], the application and recommendation of probiotics need further research evidence support [49-51].