Did you know that up to 70% of your immune system is in your gut?
Humans have more bacterial cells – a lot more – than human cells. Bacteria live on the skin, in the nose and ears, and most of all, in the gut. In fact, the combined number of genes in the microbiota genome is 150 times larger than the person in which they reside.
We tend to think that these bacteria stay fairly separate from us and just aid with digestion, but in fact, there is a lot of interaction between the body’s immune system and bacteria in the gut. Researchers are in the early stages to figure out how the composition of the gut changes in different diseases, how the body’s immune system interacts with these tiny hitchhikers and how that relationship may correlate with disease.
The assistant professor of pathology at Johns Hopkins University School of Medicine mentioned that a huge proportion of our immune system actually is in our GI tract. Certain cells in the lining of the gut spend their lives excreting massive quantities of antibodies into the gut. More studies are undergoing to find out what types of antibodies are being made and how the body control the interaction between ourselves and the bacteria.
Role of gut microbiota in immune homeostasis
Keeping a delicate balance in the immune system by eliminating invading pathogens while still maintaining self-tolerance to avoid autoimmunity is critical for the body’s health. The gut microbiota resides in the gastrointestinal tract provides essential health benefits to its host, by regulating immune homeostasis. Studies have reported that alterations of these gut microbiota can cause immune dysregulation and leads to autoimmune disorders.
The microbiome plays critical roles in the training and development of major components of the host’s innate and adaptive immune system, while the immune system orchestrates the maintenance of key features of host-microbe symbiosis. The study of mechanistic causal relationships between commensal microbiota and host immunity is demonstrated by the use of germ-free (GF) animal models where the absence of commensal microbes in these animal models was associated with intestinal defects of lymphoid tissue architecture and immune functions. Thus, perturbation of the gut microbiome by environmental factors (such as antibiotic use, diet or changes in geography), impairment of host-microbiome interfaces, or alterations of the immune system can result in systemic dissemination of commensal microorganism, susceptible to pathogenic invasion and aberrant immune response.
Maintaining a healthy gut microbiome requires consuming a healthy diet, with a wide variety of whole food is the key, not forgetting to take time to chill out, consume alcohol within healthy guidelines and only use medications as prescribed by your healthcare professional.
Probiotics – alternative to fuel your microbiota gut
Nonetheless, living in a fast-paced world cause us not to have diet that is not up to scratch, stress runs high, drinking more alcohol than usual, getting ill and the need to take medication which may or may not include antibiotics.
Our gut health and immune system is also affected by ageing, a factor which we have no control over!
Thus, if food sources of probiotics, including yoghurt, kimchi, miso or kombucha, do not sound appealing, taking a quality probiotic can be useful in supporting your gut health, providing daily dose of probiotics and to help support your immune system function.
How much probiotics should I need?
A wide range of dosages for probiotics have been studied in clinical trials, ranging from 100 million to 1.8 trillion CFUs per day, with most studies examined dosages in the range of 1 to 20 billion CFUs per day. Generally, high dosages of probiotics (that is more than 5 billion CFUs per day in children and more than 10 billion CFUs per day in adults) were associated with a more significant study outcome. There is no evidence that higher dosages are unsafe, however, they may be more expensive and unnecessary. Furthermore, dosage recommendations can vary for specific conditions. For instance, in acute infectious diarrhea treatment, higher doses of probiotic given for short courses are more effective than lower doses. Patients are advised to read product labels carefully to make sure they are getting the proper dose. A recent study analyzed a range of brands of probiotics and found that of the 19 brands examined, five did not contain the number of live microorganisms stated on the label. CFU count may tell you what kind of numbers a probiotic supplement starts with, but the only number that matters is how many bacteria make it to your gut alive. Thus, it is essential to research brands before purchasing a specific product.
Contraindications, adverse effects and interactions
There are no absolute contraindications to probiotics comprised of Lactobacillus, Bifidobacterium and S. thermophilus. There are typically few or no adverse effects, minimal has reported flatulence or mild abdominal discomfort. It is prudent to avoid probiotics in patients who are immunocompromised or children with short-gut syndrome.
Take home message
There is a growing number of scientific evidence supporting the incorporation of probiotics in nutrition as means of derivation of health benefits. There is no doubt that will be a significant increase in the role of probiotics in nutrition and medicine over the next decade.
References:
1. Bertazzoni E, Donelli G, Midtvedt T, Nicoli J, Sanz Y. Probiotics and clinical effects: is the number what counts? J Chemother. 2013 Aug;25(4):193-212. doi: 10.1179/1973947813Y.0000000078. PMID: 23906073.
2. Shi LH, Balakrishnan K, Thiagarajah K, Mohd Ismail NI, Yin OS. Beneficial Properties of Probiotics. Trop Life Sci Res. 2016 Aug;27(2):73-90. doi: 10.21315/tlsr2016.27.2.6. PMID: 27688852; PMCID: PMC5031164.
3. Isolauri E, Sütas Y, Kankaanpää P, Arvilommi H, Salminen S. Probiotics: effects on immunity. Am J Clin Nutr. 2001 Feb;73(2 Suppl):444S-450S. doi: 10.1093/ajcn/73.2.444s. PMID: 11157355.
probiotic, gut health, immune system, microbiota, lactobacillus, bifidobacterium, streptococcus thermophilus
Comments