Here we are just finishing up another year. The last year has added a great deal to our understanding of human microbiome and its role in health and disease. We have handpicked what we believe are the top 6 most amazing research developments 2016 has seen in the world of the microbiome.
Study #1: Gut Microbiota Regulate Motor Deficits and Neuro-inflammation in a Model of Parkinson’s disease
Study Link: http://www.cell.com/cell/abstract/S0092-8674(16)31590-2
Prelude: Parkinson’s Disease (PD) is predominantly linked to genetic factors. However, the environmental factors, especially the role of gut dysbiosis, in the progression of this disease remains unexplored.
The research: In Parkinson’s Disease (PD), a group of proteins called the a-synuclein (aSyn) aggregate in the brain leading to brain abnormalities.
In this study, researchers used a group of mice that overexpressed this protein. In one part of this study, the researchers colonized a group of germ-free, aSyn over-expressing mice with the microbiota from PD-affected or normal donors. Interestingly, the mice transplanted with microbiota from PD donors developed all the features consistent with PD compared to the mice receiving microbiota from healthy donors.
This suggests that gut dysbiosis plays a key role in the development and progression of Parkinson’s disease.
Why is this study important? The current treatment methods for this debilitating condition are mostly symptomatic. Finding ways that could help prevent the disease progression in the early stages could aid a great deal in reducing the burden of this disease. The findings of this study could add to our arsenal of the available treatments for this condition.
Study # 2: Exercise-induced stress behavior, gut-microbiota-brain axis and diet: a systematic review for athletes.
Study Link: https://jissn.biomedcentral.com/articles/10.1186/s12970-016-0155-6
Prelude: Intensive training, as competitive athletes do, causes a lot of psychological effects and gut distress. Intensive training causes the release of a number of different hormones. This leads to psychological manifestations like depression and anxiety and digestive disturbances like diarrhea and vomiting.
The research: This review article summarizes the potential link between gut microbiota health and athletic performance. Here is the summary:
- There exists a two-way link between gut microbiota and athlete’s emotional health i.e. distress leads to dysbiosis and vice versa. This leads to manifestations of depression, anxiety, fatigue, and insomnia.
- The tight barrier of gut prevents the spilling of toxins from the gut into the bloodstream. Stress, as the result of intensive training, leads to the loosening of this junction, leading to ‘leaky gut syndrome’ where toxins gain entry into the body systems. This leads to metabolic disturbances and impairment in performance.
- Around 20-50% of athletes complain of gastrointestinal (GI) symptoms at some point during their careers. Exercise causes reduced supply of blood to the gut leading to abdominal pain, GI upset, vomiting, and diarrhea. All these features are further accentuated by gut dysbiosis.
Why is this study important? This research has explained the role of athletes’ diet in upholding their physical and psychological health. Unfortunately, the diet of athletes contains an extremely low proportion of plant-based polysaccharides which is linked to reduced gut microbiota. The results of this research may help emphasize the need to remodel the dietary patterns in athletes to include more probiotic and prebiotic sources in their daily dietary regimen.
Study # 3: A purified membrane protein from Akkermansia muciniphila or the pasteurized bacterium improves metabolism in obese and diabetic mice
Study Link: http://www.nature.com/nm/journal/vaop/ncurrent/full/nm.4236.html
Prelude: With obesity and its related complications like diabetes turning into a pandemic, the world is in a dire need of novel methods of coping with these issues. The role of gut microbiota in controlling obesity and its complications is still rather an unexplored area.
The research: Akkermansia muciniphila is one of the most abundant members of human gut microbiota, representing 1-5% of the total intestinal microbes. The researchers have previously demonstrated that obese mice have a lower baseline level of A. muciniphila. Also, supplementation with these bacteria can improve body weight, metabolism, and diabetes status. The biggest problem, however, in the treatment is the administration of these bacteria. The conventional methods of preparing the bacteria through autoclaving (heating the bacteria) render them rather inactive.
In this study, scientists used the method of pasteurization to treat the bacteria. This method exposes bacteria to lower temperatures (70 C) for lesser durations (30 minutes). Interestingly, the efficacy of bacteria increased instead of decreasing. The bacteria treated with pasteurization showed better metabolism boosting effects, improved fat burning properties, and super sugar lowering effects.
Why is this study important? Science might be on the brink of a major breakthrough in controlling obesity epidemic and the gut microbiota might be a centerpiece in this development. Finding new ways to deliver probiotics to their target site (gut) and restoring your digestive health, without undergoing damage during the preparation or administration might aid in dealing with this pandemic more efficiently.
Study # 4: The safety and feasibility of probiotics in children and adolescents undergoing hematopoietic cell transplantation
Study Link: http://www.nature.com/bmt/journal/v51/n2/full/bmt2015275a.html
Prelude: Transplantation of stem cells is turning into a gold-standard procedure for blood-based disorders. Although successful, these procedures are linked with risks like Graft vs. Host Disease (GvHD). To avoid such unwanted side effects, the recipients are often given multiple sessions of immunosuppressant therapy after transplantation. This then makes them prone to a lot of immunosuppressant therapy-related side effects like gut disturbance.
The research: Researchers gave Lactobacillus plantarum (LBP) based supplements to children and adolescents receiving blood cell transplants. None of them developed serious side effects to this supplement. In addition, most of the recipients showed improvement in immunosuppressant therapy-related side effects. Above all, the recipients showed a striking reduction in the incidence of GvHD.
Why is this research important? Transplantation and the subsequent immunosuppressant therapy can have a lot of unwanted side effects. This is the first study of its kind that has shown the potential of probiotic supplementation in improving the survival of transplants as well as reducing the incidence of immunosuppressant therapy related side effects.
Study # 5: A Dietary Fiber-Deprived Gut Microbiota Degrades the Colonic Mucus Barrier and Enhances Pathogen Susceptibility.
Study Link: https://linkinghub.elsevier.com/retrieve/pii/S0092-8674(16)31464-7
Prelude: Prebiotics are essential for the gut and probiotic health. But, how exactly do prebiotics achieve this feat? This research is all about exploring the role of prebiotics.
The research: In this study, scientists studied the effects of fiber deprivation on the behavior of gut microbiome.
The mice used initially did not have a microbiome of their own. Later, they were inoculated with 14 strains of probiotic bacteria. Then, the mice were fed on high-fiber diet for 14 days. During this period, the microbiota population flourished. Afterward, the mice were divided into groups that were either given a fiber-free or a fiber rich diet.
The group of mice eating fiber-free diet had a higher proportion of bacteria that could digest the gut wall.
Why is this research important? This is the first research of its kind that explicitly explains the role of prebiotics in upholding gut health and promoting the growth of probiotics. According to this research, not every kind of prebiotics, but only those that comprise of complex polysaccharides are helpful in improving the growth of probiotic bacteria. In other words, there should be more emphasis on the intake of healthy plant-based prebiotic elements.
Study # 6- Diet-induced extinctions in the gut microbiota compound over generations
Study Link: http://www.nature.com/nature/journal/v529/n7585/full/nature16504.html
Prelude: Until now, it's generally understood that the modern Western diet leads to an imbalance in the balance of gut microbiota. The research also shows that most of these changes are reversible with proper dietary changes. But this research shows another side of the picture.
The research: Scientists deprived mice of certain food nutrients that led to a reduction in the gut levels of bacteria. The mice passed this decrease in the gut-friendly bacteria to their successive generations. To their surprise, the species of bacteria lost were not recovered even when the mice were given the missing nutrients.
Why is this study important? That’s something striking. The results of this research show that our current dietary choices do not just affect our health but we are unknowingly passing on an array of conditions to our newer generations. That is indeed something that needs to be addressed right away.
2016 has added a great deal to our understanding of gut microbiome. We can't wait to see what happens in 2017!
Happy New Year!