Introduction: Trillions of micro-bacteria flourish in our organism since the day we are born and are almost like our unique fingerprint or a neglected important second brain that can influence our behaviour. They are often thought as sources of disease but many are beneficial and keep us healthy(7) .Most of them are found in the digestive system ,or “gut” which comprises of stomach ,pancreas ,liver,gall bladder,small and large intestines.Prof Tim Spector says “I can tell more about someones health by getting a detailed screen of their microbes than by screening their genes “ (1).
How does it affect health? Now scientists have discovered how to manipulate gut bacteria genes and indirectly improve health while this can’t easily be done with a rare mutation in the human genome(1). Except the major role these bacteria have in digesting the food ,they also regulate our immune system.They have been linked to allergies,depression,Parkinsons and autoimmune conditions such as rheumatoid arthritis and Type 1 diabetes.Each individual has a unique micro biome which can be shaped by the variety of foods we take into our diet,antibiotics ,stress and toxins we are exposed to(6). We are taking one example in order to explain the importance of a healthy gut: Type one diabetes (T1D)- a chronic autoimmune condition in which pancreas produces little or no insulin.Different factors genetics and environmental also gut micro biome and viral infections are a potential cause.The body immune system that normally protects towards hazards ,in this case targets the insulin producing cells in the pancreas(islet beta cells or islets of Langerhans) (9).Studies show that in 2017 roughly 425 million adults (aged 20-79) were living with diabetes(type 1 and 2) and more than 1,106,500 children were living with type 1 diabetes (10).
Figure 1 The importance of bacteria .Image adapted from (7).
Symptoms: Levels of glucose in patient blood become too high, Blurred vision, Feeling thirsty and hungry, Feeling fatigue and weakness, Losing a lot of weight, Fast heartbeat
Current treatment: Taking lifelong insulin therapy, Eating healthy foods and keeping a balanced diet, Monitoring blood sugar levels regularly(goal between 80 and 130 mg/dL)and no higher than 180mg/dL after meals, Regular physical activity
Latest studies: In the first study researchers at Baylor College of Medicine analysed 16s rRNA information from sequencing of 12,500 samples from 905 children between 3 and 56 months age. Three different distinct stages of microbial development were found (4)(11) : 1.Development phase(3 to 14 months age), 2.Transitional phase(15 to 30 months of age), 3.Stable phase(31 to 46 months of age). This results don’t conclude that gut microbiota maturation ends at 3.5 years of age, previous studies have shown that it is not completely established by age of 5 years(4)(11) .
Secondly the Environmental Determinants of Diabeties in the Young (TEDDY) study analysed and collected monthly from age three months till the clinical end point 10,913 metagenomes from 783 samples of non-Hispanic children .Microbiomes of control children contained genes related to biosynthesis and fermentation of short -chain fatty acids .While in children with T1D deficiency of bacteria that produce short -chain fatty acids(SCFAs) and increased numbers of Bacteroides species was observed.This clearly shows the protective effects of short-chain fatty acids in the early onset human T1D (3).
First year of life was characterised by individualised micro biome profiles mostly dominated with bifidobacterium species(B.bifidum ,B.breve or B.longum) and phylum probacteria.In breasted fed infants B.Longum was present and thought to be associated with processing of human milk oligosacharide.When solid food is introduced a range of 20 microbial metabolic enzymes changed ,for example enzyme l-lactate dehydrogenase which helps in milk fermentation decrease in number followed by an increase in enzyme transketolase which contributes in metabolism of fibre .Therefore human milk is one of the most important contributors to formation of infant guy microbiome (2)(3).
The effects of antibiotics in the early life micro biome -antibiotics were shown to disturb the stability of gut bacteria.Bifidobacterium members were particularly vulnerable to antibiotics intake.This shows that approaching antibiotics prescription with caution especially un early childhood during breastfeeding is important (3).
Figure 2 Factors that contribute to diabetes pathogenesis.Antibiotics,Western diet and microbial exposure.This results in gut bacterial imbalance which leads to high low-grade inflammation ,low short-chain fatty acid and glucagon-like peptide 1 production .Image adapted from (8).
This studies helped in laying the foundation for identifying more microbial components which can be protective or a cause for T1D pathogenesis.
COPYRIGHT: This article is the property of We Speak Science, a non-profit institution co-founded by Dr. Detina Zalli and Dr. Argita Zalli (Imperial College London). The article is written by Kasandra Malasi, University of Leicester, UK.