Probiotics are generally consider to be bacteria or microorganisms that are good for your health. Probiotics may be included in foods such as yogurt or kefir, which can be digested. Probiotics often include bacteria such as lactobacillus and bifidobacterium which may be found in different dairy products and fermented foods.
Probiotics are different from prebiotics which are foods that cannot be digested and feed good bacteria, particularly in the lower intestine. Prebiotic foods can include asparagus, Jerusalem artichoke and dandelion greens.
The history of the use of probiotics goes back many thousands of years to different systems of traditional and natural health. In modern times, the concept was introduced in 1907 by Nobel recipient Élie Metchnikoff, who postulated that yogurt-consuming Bulgarian peasants lived longer lives because of this traditions.
Probiotics are often prescribed by doctors after antibiotic use to help replace “good” bacteria that may have been destroyed. They may also be prescribed for a number of disorders of the digestive system including:
Irritable bowel syndrome
Inflammatory bowel disease (IBD)
Infectious diarrhea (caused by viruses, bacteria, or parasites)
Selected Scientific Research
More recently a systematic review of 15 human randomized controlled trials from July 2016 found that certain commercially available strains of probiotic bacteria improved behavioral outcomes in certain psychological disorders, for example: anxiety, depression, autism spectrum disorder, and obsessive-compulsive disorder – and improved certain aspects of memory (Wang H, Lee IS, Braun C, Enck P (July 2016). “Effect of probiotics on central nervous system functions in animals and humans – a systematic review”. J. Neurogastroenterol Motil. doi:10.5056/jnm16018. PMID 27413138).
The consumption of probiotics may modestly help to control high blood pressure (Khalesi S, Sun J, Buys N, Jayasinghe R (2014). “Effect of probiotics on blood pressure: a systematic review and meta-analysis of randomized, controlled trials”. Hypertension (Systematic review & meta-analysis). 64 (4): 897–903. doi:10.1161/HYPERTENSIONAHA.114.03469. PMID 25047574).
Preliminary human and animal studies have shown that probiotic can be effective in reducing cholesterol levels. (Kumar M, Nagpal R, Kumar R, Hemalatha R, Verma V, Kumar A, Chakraborty C, Singh B, Marotta F, Jain S, Yadav H (2012). “Cholesterol-lowering probiotics as potential biotherapeutics for metabolic diseases”.
Experimental Diabetes Research. 2012: 902917. doi:10.1155/2012/902917. PMC . PMID 22611376 and Agerholm-Larsen L, Bell ML, Grunwald GK, Astrup A (2002). “The effect of a probiotic milk product on plasma cholesterol: a meta-analysis of short term intervention studies”. European Journal of Clinical Nutrition. 54 (11): 856–860. doi:10.1038/sj.ejcn.1601104. PMID 11114681).
A well-controlled clinical trails have conclusively demonstrated that probiotics help the following conditions:
Acute infectious diarrhea
Irritable bowel syndrome
(Wilkins, T et al., Probiotics for Gastrointestinal Conditions: A Summary of Evidence. American Family Physician Aug 2017; 96:3,170-178; Pinto-Sanchez MI, Hall GB, Ghajar K, et al. Probiotic Bifidobacterium longum NCC3001 Reduces Depression Scores and Alters Brain Activity: a Pilot Study in Patients With Irritable Bowel Syndrome. Gastroenterology. 2017. doi: 10.1053/j.gastro.2017.05.003.; Kennedy, PJ et al., Irritable bowel syndrome: A microbiome-gut-brain axis disorder? World J Gastroenterol Oct 2014; 20(39): 14105–14125)
Labeling and Approval
Most companies report the number of bacteria that are contained in their pills at the date of manufacture. Unfortunately, different storage conditions will reduce this number so the actual number of bacteria at the time of consumption is difficult to calculate. The European Commission has the stricter labeling requirements and has placed a ban on putting the word “probiotic” on the packaging of products because they do not feel there is enough scientific evidence to justify any assumed health benefits. The FDA allows the use of the word but has tried to limit the listing of benefits for specific diseases. Despite these restriction there has been a large increase in the use of these products, as well as foods containing probiotics, worldwide.
Since in its natural state the gut contains many hundreds of different strains of bacteria, one of the main limitation on current products is the lack of diversity of types of bacteria. Another problem is the means of delivery. Are the bacteria in the probiotic product able to reach the lower intestine where they are most needed without being digested or destroyed? Finally, it has been argued that because there are some 30 trillion bacteria in the lower digestive tract that even if a few million were able to make it to this destination would they be enough to make a change in the existing ecology. Some physicians have suggested that it may be more effective to introduce the bacteria through enemas to make sure they are able to reach the lower intestine in the most efficient manner. (e.g. The Brain Maker by Dr. David Perlmutter). Currently, there is not enough scientific research to determine the best probiotics and the most effective manner of delivery.
Relationship to Amazon
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