Microbiome and Health Insights

Moving the microbiome field from descriptive to mechanistic in order to exploit microbiome analysis to clinic usefulness. This paper we just publish show how epigenetic reprogramming by some microbiota components can start the march from genetic predisposition to clinical outcome, opening the possibility of exploiting the gut microbiome for future precision medicine and primary prevention applications https://lnkd.in/ejzYWsEz

What's the clinical usefulness of a microbiome? We’re still trying to figure that part out! The microbiome is composed of all of the fungi, viruses and bacteria that live on or in an organism inclusive of their omic interactions with one another. Most discussions around the microbiome are related to health, wellness and disease, but to actually know anything about the clinical impact of the microbiome on those things, we need to do a lot of research! There is broad agreement that the microbiome is important, but we currently have very little knowledge about ‘cause and effect’ or how broadly we can impact the microbiome to actually influence health or prevent disease. And understanding cause and effect is very important because that tells us whether what we’re looking at when we sample a microbiome is just the ‘result’ or if it’s something we can manipulate to do our bidding. Current research suggests it’s a little of both! Inflammation - A dysregulated microbiome has been associated with skin rashes and mild to severe digestive problems. Much of this appears to be linked to metabolite production, some of which can activate the immune system to create undesirable side effects in the host, but create a more desirable living environment for the microbes. Host metabolism - Much of human microbiome research is focused on the gut microbiome and how the gut microbiome affects our ability to properly metabolize the food that we eat. We rely on bacteria to provide certain digestive enzymes and to help produce essential things like amino acids and vitamins that are not found abundantly in our diets. Oncology - More recently, the microbiome has been studied in the context of oncology and how the tumor microenvironment might be influenced by bacteria - both in tumorigenesis and proliferation. But there is also ongoing research in how the microbiome might influence the effectiveness of cancer treatments because of how certain microbes metabolize chemotherapy drugs or modulate the immune system to reduce the effectiveness of therapies. Pathogenic infections - This is probably the space where we have the best clinical evidence. We know that pathogenic bacteria can cause major problems both on our skin (think MRSA) and in our digestive tract (think H. pylori or pathogenic E. coli). When these bacteria get a foothold, they take over but there is evidence that a healthy microbiome (or fecal transfer of one for gut infections) can resist these ne'er do wells. While the sample sizes in most of these studies is very small, we’re just at the beginning of attempting to fully understand the role of the microbiome in health and disease. Good data and properly designed studies are the first step in allowing us to make the important clinical associations that help us identify and/or engineer bacteria to fight disease or improve our health. --- Want this content in your inbox? Visit my website ⬆️

Fascinating new paper reveals a gut microbiome connection to heart disease. Microbes produce imidazole propionate (ImP), which directly triggers atherosclerosis through immune activation - even without high cholesterol. This microbial metabolite binds to specific receptors on immune cells, causing inflammation and plaque formation. The discovery opens new paths for early detection and targeted therapies based on our microbiome signatures. https://lnkd.in/gJCE4Enz

🦷🌊 Your Mouthwash Could Be Harming Your Microbiome A recent study published in Nature Portfolio Scientific Reports has unveiled the startling impact antibacterial mouthwash can have on our guts. Offering a new perspective on the implications of our daily oral hygiene practices on the oral-gut microbiome axis. 🔬 Key Findings Microbiome Disruption - Mice treated with oral chlorhexidine, a common antibacterial mouthwash ingredient, while on a Western diet, experienced significant shifts in their gut microbiome. This included decreased microbial diversity and alterations in specific bacterial populations associated with metabolic processes. Metabolic Impact - Interestingly, these mice showed reduced weight gain and lower body fat percentages despite NO change in their caloric intake, pointing towards an impact on nutrient absorption and metabolism. Health Implications - The findings suggest that regular use of antibacterial mouthwash could have broader effects on our health, potentially influencing nutrient absorption and contributing to systemic changes linked to obesity. 🔍 Looking Ahead Our lifestyle choices, including our oral hygiene habits, impact much more than just our mouths. This study alone sheds light on the intricate connection between oral health, the gut microbiome, and metabolic wellness. Bringing a holistic approach to our daily health routines can help us do a better job of considering our overall well-being, microbiome included. I’m curious what other daily hygiene products may be having unintended consequences on our intestinal health. 🔗 https://lnkd.in/dZeGaVz4 #guthealth #microbiomeresearch #obesity #oralhygiene #wellness #research #injoy

People can adapt to high fiber intake (25-35 g/day) within 3 weeks. Dietary fiber is well recognized as an important dietary component for the prevention of chronic disease. The Food and Nutrition Board of the National Academy of Medicine set the Adequate Intake (AI) for fiber at 25-38 g/day [~14 g for every 1,000 calories (25 g for women, 38 g for men)]. However, daily fiber intake in most developed countries is only half of that (PMID: 32728749), resulting in what is known as the “fiber gap.” Higher doses of fiber may be necessary to achieve consistent health benefits attributed to fiber. For instance, 44-50 g/day but not more usual fiber intakes have been recorded to improve glycemic parameters in diabetic populations. However, amounts of fiber needed to achieve consistent benefit or induce relevant changes to the gut microbiota induce symptoms in people that include bloating, flatulence, stomach ache, etc. As such, it’s been unknown as to whether free-living individuals can sustain the amount of fiber intake needed to achieve routine/consistent benefits of fiber intake. A recent study published in the journal Gut Microbes investigated high dosed fiber (arabinoxylan) supplements in men (35 g) and women (25 g) during a 6-week RCT. Findings: *Adaptation to fiber: Participants initially experienced increased GI symptoms, including flatulence and bloating, which significantly declined over time, indicating adaptation to high-dose fiber. *Microbiota composition: The study identified a strong correlation between the abundance of Bifidobacterium longum and improved GI tolerance. Higher baseline levels of B. longum were associated with less severe symptoms and better adaptation. *Dietary influence: Participants with higher baseline consumption of whole grains and lower intake of animal-based foods demonstrated better GI tolerance to fiber, suggesting the influence of habitual diet on fiber tolerance. *Fecal short chain fatty acids and pH: fiber consumption led to significant changes in fecal short-chain fatty acids (SCFAs) and pH levels, further linked to symptom severity and adaptation. The findings suggest that humans can adapt to high fiber intake and this process is linked to our microbiome. Likewise, microbiome benefits can be altered by supporting a GI environment that selects for fiber-metabolizing bacteria. https://lnkd.in/gSJFWgkZ

Gut Microbiota Acts Like an Auxiliary Liver. Microbes in mammalian gut can significantly change their hosts’ amino acid and glucose metabolism, acting almost like an extra liver, according to a new preclinical study by Weill Cornell Medicine investigators. New York, New York. April 23, 2024. Excerpt: The study, published April 23 in Cell Host & Microbe, adds to the growing list of ways in which the microbiome influences physiology, and could lead to new strategies to treat conditions such as inflammatory bowel disease and diabetes. In recent years, scientists have found billions of microbes living on and in the human body profoundly influence our physiology. Senior author Dr. Chun-Jun Guo, an assistant professor of microbiology & immunology in medicine and a member of the Jill Roberts Institute for Research in Inflammatory Bowel Disease at Weill Cornell Medicine, wanted to take a deeper look at how essential microbes in the gut affect our access to the nutrients extracted from the food we ingest. “They ‘eat’ before us, taking nutrients from food we consume, and leaving us with what remains after they satisfy their own nutritional needs,” said Dr. Guo, a member of the Friedman Center for Nutrition and Inflammation at Weill Cornell Medicine. To better understand this process, first author Dr. Ting-Ting Li, a postdoctoral associate in the Guo lab, and collaborators, assessed how efficiently different bacteria that inhabit our intestines, called human gut commensals, deplete amino acids, the building blocks of proteins. Due to poorly characterized metabolic functions of many gut bacteria, the team experimented with various settings to find optimal conditions for their study. After screening more than 100 human gut microbes, investigators pinpointed several that are highly efficient at metabolizing various dietary amino acids. When these microbes colonized the gastrointestinal tracts of germ-free mice—mice without microbes-- the levels of amino acids dropped in the host's intestine and bloodstream. Note: The team identified specific bacterial metabolic genes that deplete amino acids. “We found in one single bacterium, over 20 genes encoding a similar enzymatic function,” Dr. Guo said. “And because we improved our CRISPR-Cas9 gene deletion techniques for gut bacteria, we performed a large gene deletion screen and identified metabolic genes in the bacteria responsible for depleting amino acids." The scientists took their findings from cultured cells into animals, giving germ-free mice genetically modified strains of bacteria, one at a time. “We can now precisely manipulate individual genes for depleting amino acids in the gut,” Dr. Guo said. “This allows us to assess the individual function of these genes and to see how they impact host amino acid homeostasis.” Link to April 23 published research in enclosed announcement. https://lnkd.in/egYJq5Ce

Evidence suggests that the gut #microbiome influences socio-affective behavior. A team from INSEAD, France; The Brain Institute of America, The University of Bonn, Germany, sought to understand how the composition of the microbiome influences social skills. They recruited 101 healthy men. "We chose only men for our study, particularly due to the hormonal factors in women that are significant in decision-making," explained Hilke Plassmann, a professor at INSEAD and coauthor of the study published in PNAS Nexus. Half of the participants received a mixture of #prebiotics and #probiotics, including Lactobacillus and Bifidobacterium, while the other half received a placebo for 7 weeks. Their microbiome composition was analyzed at the beginning and end of the experiment. "The participants continued their usual diet. The prebiotics allowed the bacteria to colonize the gut more easily," the researcher explained. Measuring Sensitivity to Injustice. Participants were invited to take part in a behavioral test called the "ultimatum game," before and after receiving the supplementation. This game experimentally measures sensitivity to injustice. The study results showed that participants who received the supplements were more likely to reject unequal offers at the end of the 7 weeks, even when the imbalance was slight. The placebo group behaved identically during the first and second test sessions. "This suggests that modifying the gut microbiome made the participants less rational and more human, more sensitive to social considerations." Role of Tyrosine. Participants who, at the beginning of the study had the greatest imbalance between the two types of bacteria dominating the gut flora (Firmicutes and Bacteroidetes) saw their microbiome composition evolve more with the supplements. These individuals showed the greatest sensitivity to injustice during the ultimatum game. Blood tests before and after supplementation revealed a decrease in tyrosine levels, a dopamine precursor, after 7 weeks of supplementation. This study needs to be complemented by further research, particularly on other social groups. "For future studies, we can try to understand why this psychological reaction is observed," she said. The importance of the microbiome's role is increasingly studied, including in psychiatric disorders. A meta-analysis 2021 in JAMA #psychiatry showed that imbalances in the microbiota can be found in patients experiencing #depression, #anxiety, #bipolardisorder, #schizophrenia. "we don't know if it's the change in the microbiota that influences the disease or vice versa. It's the chicken or the egg problem," commented Plassmann. https://lnkd.in/eWQ9uBXc #nimh #mentalhealth The National Institutes of Health Centers for Disease Control and Prevention

A new study by researchers Margo Heston, Kendra Hanslik, Katie Zarbock, et al. at the University of Wisconsin School of Medicine and Public Health "suggests a link between #Gut #Inflammation and changes in the brain and declines in memory, further supporting a connection between the gut and brain in #AlzheimersDisease." "The study showed that as levels of calprotectin, an inflammatory marker, increased in the volunteer study participants’ stool samples, so did the amount of #Amyloid plaque accumulating in the brains of those with #Alzheimers disease. Levels of Alzheimer’s disease biomarkers in cerebrospinal fluid also rose. Meanwhile, test scores of the volunteers’ verbal memory function dropped." "Even volunteers who did not have Alzheimer’s disease had lower scores on a memory test correlated with higher levels of calprotectin, according to Barbara Bendlin, professor of medicine, UW School of Medicine and Public Health." Learn More in Scientific Reports | Nature Portfolio https://lnkd.in/diS9H88q Gut inflammation associated with age and Alzheimer’s disease pathology: a human cohort study - Margo Heston, PhD, Kendra Hanslik, Katie Zarbock, Federico Rey, Barbara B. Bendlin, Tyler Ulland, et al. University of Wisconsin-Madison Wisconsin Alzheimer's Disease Research Center Roche Sahlgrenska Academy at University of Gothenburg Sahlgrenska University Hospital UCL HKCeND - Hong Kong Center for Neurodegenerative Diseases (香港神經退行性疾病中心) ScienceAlert https://lnkd.in/dByghhip

Diverse microbiomes are key for robust pathogen exclusion--Just published in Science. This study explores colonization resistance, a crucial aspect of the microbiota's role in host defense against pathogens. The researchers discovered that colonization resistance is a higher-order effect of a diverse community of bacteria, with key species like Escherichia coli playing essential roles. Through in vitro and in vivo experiments, they found that a diverse microbiota, with the right composition, collectively consumes nutrients required by incoming pathogens, limiting their growth in the host. The predictability of colonization resistance arises when the symbiotic community shares similar proteins with the pathogen. The study emphasizes that microbiome diversity, community composition, and nutrient utilization profiles are critical factors in providing protection against pathogen colonization. Manuscript: https://lnkd.in/g4fApU6w #microbiome #pathogen #diversity

What You Eat Can Shift Your Mood Ever feel anxious... and then your stomach starts acting up too? Or, have you noticed you feel foggy, low or irritable after days of junk food? That’s not in your head. That’s the brain-gut axis in action. Your brain and your gut are in constant conversation. What happens in one, affects the other. 🧠 The brain sends signals to your gut when you’re stressed or anxious. 🍎 The gut sends signals to your brain based on what you eat and how healthy your gut bacteria are. It’s a two-way street. And it’s a powerful one. As a psychiatrist, I’ve seen this firsthand, both with my patients and in my own life. Food, stress, inflammation and mood are deeply connected. The science is clear: a healthy gut can support a healthier brain. And healing emotionally can also calm the gut. 🔸 3 Simple Ways to Strengthen the Gut-Brain Axis 🔸 ✅ Eat More Fiber and Fermented Foods Fiber feeds the good bacteria in your gut. Fermented foods like yogurt, kimchi and kefir add healthy microbes. Together, they support mood and cognitive health. ✅ Manage Stress Daily Chronic stress can disrupt gut function. Even 5-10 minutes of deep breathing, walking or stretching can help regulate your nervous system - and your digestion. ✅ Prioritize Sleep Poor sleep affects both gut health and brain function. Aim for consistent sleep patterns and limit screens before bed. Rest repairs both systems. “Every time you eat or drink, you are either feeding disease or fighting it.” - Heather Morgan, MS, NLC You don’t need a perfect diet or stress-free life to improve how you feel. Small steps matter. You can support your mental health - not just with what’s in your head, but with what’s on your plate. ♻️Please feel free to share this post to help spread awareness and support around mental health. You never know who might need this reminder today.♻️ 🔔Follow me for more insights and updates on mental health and wellness!🔔 #mentalhealth #motivation #diet #brain #gut #psychiatry (Image Credit: Neuroserve) (For educational purposes only. Not medical advice.)