Breaking News
July 20, 2018 - MRI and blood test combination results in improved prostate cancer diagnosis
July 20, 2018 - Update Health Professional and Consumer on Recent Recalled Products
July 20, 2018 - Researchers trace Parkinson’s damage in the heart
July 20, 2018 - Wearable device designed to measure cortisol in sweat
July 20, 2018 - Scientists demonstrate a new regulation mechanism for skeletal muscles
July 20, 2018 - Exposure to mobile phone radiation may negatively impact memory performance in adolescents
July 20, 2018 - SUSU scientists find alternative method to treat post-traumatic stress disorder syndrome
July 20, 2018 - Gestational diabetes may increase offspring’s heart disease risk
July 20, 2018 - New vaccine could protect unborn babies from Zika virus
July 20, 2018 - Researchers find high mercury and methylmercury concentrations in traditional Tibetan medicine
July 20, 2018 - Brief Safety Plan Intervention in ER Can Cut Suicidal Behavior
July 20, 2018 - Toward a better understanding of Parkinson’s disease
July 20, 2018 - Med school communications office wins four national awards | News Center
July 20, 2018 - Professional baseball players with faster hand-eye coordination may have better batting performance
July 20, 2018 - Scientists identify melanoma biomarkers that could help tailor immunotherapy treatments
July 20, 2018 - Research reveals long-term efficacy of drug used to treat common cause of kidney failure
July 20, 2018 - Timing of dinner associated with breast and prostate cancer risks
July 20, 2018 - Health Tip: Performing the Heimlich Maneuver
July 20, 2018 - Nearly all adolescents have eating, activity or weight-related issues
July 20, 2018 - High-performance porous polymeric material for chromatography applications
July 20, 2018 - New molecule shows great promise for future treatment of many cancers
July 20, 2018 - New research project investigates alternative treatments for eye infections
July 20, 2018 - Immune T cells are built to react as fast as possible, shows study
July 20, 2018 - ZHX2 protein could offer a new treatment strategy for kidney cancer
July 20, 2018 - EKF’s Quo-Lab POC HbA1c analyzer meets international quality targets for diabetes testing
July 20, 2018 - Health burdens of very high risk drinking are potentially large, study reveals
July 20, 2018 - Using miniature drug-filled nanocarriers to target headaches and tumors
July 20, 2018 - Researchers uncover cause for progression of prostate cancer to incurable stage
July 20, 2018 - Studies highlight issues regarding black lung, opioid overdose, police violence and more
July 20, 2018 - AbbVie submits supplemental NDA to FDA for venetoclax to treat acute myeloid leukemia
July 20, 2018 - Researchers are one step closer to developing eye drops to treat age-related macular degeneration (AMD)
July 20, 2018 - Patients maintain muscle mass five years after surgically induced weight loss
July 20, 2018 - AMSBIO introduces new, powerful CRISPR/Cas9 gene editing kits
July 20, 2018 - PureTech Health collaborates with Roche to advance oral administration of antisense oligonucleotides
July 20, 2018 - Analysis reveals disparities in cancer death rates among minority groups
July 20, 2018 - Dr Maddy Parsons receives Royal Microscopical Society Life Science Medal
July 20, 2018 - Study finds link between DNA methylation and non-alcoholic fatty liver disease
July 20, 2018 - Military personnel with head trauma and football players with suspected CTE show similar brain changes
July 20, 2018 - Vidac Pharma Announces Initiation of Phase 2b Clinical Trial of VDA-1102 Ointment in Patients with Actinic Keratosis
July 20, 2018 - KKR is buying Envision Healthcare in a nearly $10B deal
July 20, 2018 - Older people with broken bones face higher risk of death for up to 10 years
July 20, 2018 - A simple pill for meth addicts on the cards
July 20, 2018 - UA researchers to repurpose ketamine to reduce side effects in Parkinson’s patients
July 20, 2018 - Child psychiatrist available on call to help assess separated immigrant children
July 20, 2018 - High bitter-taste sensitivity linked to increased risk of cancer
July 20, 2018 - Falling temperatures may lead to rise in numbers of deaths from stroke
July 20, 2018 - Supplemental oxygen prevents rise in morning blood pressure in OSA patients
July 20, 2018 - High fruit and vegetable intake linked to reduced risk of breast cancer
July 20, 2018 - Careful patient selection may help achieve good outcomes for vaginal mesh surgery
July 20, 2018 - Researchers raise viability of cloned mice using somatic cell nuclear transfer method
July 20, 2018 - 3HP for Latent TB Infection Treatment | 2018 | Newsroom | NCHHSTP
July 20, 2018 - An orange a day keeps macular degeneration away: 15-year study
July 20, 2018 - Researchers elucidate how the brain drives trial-by-trial adaptation to compensate for errors
July 20, 2018 - Understanding triple-negative breast cancer to develop better treatments
July 20, 2018 - Study compares outpatient antibiotic prescribing with traditional medical, retail clinic settings
July 20, 2018 - Immediate Monitoring With ECG Patch Ups A-Fib Diagnosis Rate
July 20, 2018 - KHN’s ‘What the Health?’ Drug prices and unicorns
July 20, 2018 - Scientists seek to better protect the eye from glaucoma
July 20, 2018 - Football training could improve bone mineral density in prostate cancer patients
July 20, 2018 - Single genetic change in gut bacteria can lead to obesity
July 20, 2018 - Research uncovers new target for therapeutic intervention in breast cancer
July 20, 2018 - WFN to highlight clean air for brain health on World Brain Day 2018
July 20, 2018 - Health Highlights: July 17, 2018
July 20, 2018 - Mom’s marijuana winds up in breast milk
July 20, 2018 - Black men could be healthier if seen by black physicians, new research suggests
July 20, 2018 - Alcoholics have persistent difficulties with emotional communication after long-term abstinence
July 19, 2018 - Researchers unravel how ALL invades the central nervous system
July 19, 2018 - Mother’s microbiome determines offspring’s risk of developing autism
July 19, 2018 - Refining standards of maternal-fetal care
July 19, 2018 - Stitching single cells together any which way you want to
July 19, 2018 - Study identifies RNA molecules that regulate male hormones in prostate cancer
July 19, 2018 - New machine-learning model shows promise in predicting undiagnosed dementia
July 19, 2018 - Sleep supports antioxidant processes, study suggests
July 19, 2018 - MiRagen Therapeutics Announces Initiation of Phase 2 Clinical Trial of MRG-201
July 19, 2018 - Unique brain ‘fingerprint’ can predict drug effectiveness
July 19, 2018 - Life on the border: Struggling to survive in Jordan
July 19, 2018 - CT scans may raise brain tumor risk
July 19, 2018 - Moderate alcohol intake linked with improved male fertility
July 19, 2018 - Alcohol-related cirrhosis mortality on the rise among young adults
July 19, 2018 - Study uncovers new protein complex that shields broken DNA ends
New study reveals how ‘good’ bacteria help in regulating our metabolism

New study reveals how ‘good’ bacteria help in regulating our metabolism

image_pdfDownload PDFimage_print

Research tells us that the commensal or “good” bacteria that inhabit our intestines help to regulate our metabolism. A new study in fruit flies, published June 21 in Cell Metabolism, shows one surprising way they do this.

The study, led by Paula Watnick, MD, PhD, of the Division of Infectious Diseases at Boston Children’s Hospital, reveals that innate immune pathways, best known as our first line of defense against bacterial infection, have a side job that’s equally important.

In the intestine, digestive cells use an innate immune pathway to respond to harmful bacteria. But other intestinal cells, enteroendocrine cells, use the same pathway, known as IMD, to respond to “good” bacteria — by fine-tuning body metabolism to diet and intestinal conditions.

“Some innate immune pathways aren’t just for innate immunity,” says Watnick. “Innate immune pathways are also listening to the ‘good’ bacteria – and responding metabolically.”

Metabolic syndrome, fatty liver in flies

Watnick and her colleagues knew from their previous research that bacteria living in flies’ intestines make a short-chain fatty acid, acetate, that is essential for the flies’ own lipid metabolism and insulin signaling. Flies with no bacteria in their intestines (and hence, no acetate) accumulated fat droplets in their digestive cells. The lab of Norbert Perrimon, PhD, at Harvard Medical School had previously found similar fat droplets in flies whose enteroendocrine cells lacked tachykinin, an insulin-like protein important in growth, lipid metabolism and insulin signaling.

“When there’s a problem processing glucose or lipids, fats get stuck in these droplets in cells that are not designed for fat storage,” she says.

The new study again used fruit flies, which are easy to breed and manipulate genetically, and have cell types in their intestines much like humans’. When Watnick and colleagues examined flies with mutations in the IMD innate immune pathway, they again saw fat droplets in their intestines.

Watnick believes these fat droplets, whether caused by loss of intestinal bacteria, loss of tachykinin or loss of the innate immune pathway, are the equivalent of fatty liver. Their accumulation is a sign that the body cannot properly metabolize carbohydrates and fats. In essence, Watnick thinks these flies have metabolic syndrome, commonly associated with obesity and type 1 diabetes.

Defining the immune system’s role in metabolism

How are intestinal bacteria, the innate immune system and metabolism related? Through a series of experiments, the team began to tease out exactly how bacteria exert their metabolic influence. They showed that:

  • The innate immune pathway spurs enteroendocrine cells to produce tachykinin.
  • In the absence of either bacteria or their breakdown product, acetate, no tachykinin is made.
  • When germ-free flies are given acetate, the innate immune pathway is reactivated and their metabolism normalizes.
  • A specific innate immune receptor on enteroendocrine cells, PGRP-LC, is required to receive the acetate signal.

“We know bacteria control our metabolism, but no one realized that bacteria were interacting with innate immune signaling pathways in enteroendocrine cells,” says Watnick. “Maybe these pathways are really a system that allows cells to recognize bacteria for different reasons.”

A two-pronged interaction

The study also showed that activation of the innate immune pathway in enteroendocrine cells is essential for normal fly growth and development. When Watnick and colleagues inactivated the pathway, they got growth-stunted flies. Feeding the flies acetate or directly reactivating the innate immune pathway got them growing again.

Though Watnick would now like to confirm these findings in a mammalian model, the study further sketches out what appears to be a two-pronged interaction between our microbiome and our metabolism. Good bacteria ferment nutrients in our diet and release short-chain fatty acids like acetate, which help us optimize our use and storage of nutrients. Pathogenic “bad” bacteria do the opposite: They consume fatty acids, impeding healthful metabolism. An imbalance in our intestinal microbiome has been linked to obesity and sometimes contributes to malnutrition. (More in this comprehensive review article authored by Watnick with lab members Adam Wong and Audrey Vanhove).

And because acetate is produced through fermentation, Watnick and colleagues speculate that eating more fermentable carbohydrates may boost acetate levels and promote good metabolism. Such foods may help counteract imbalances in our gut bacteria, such as those caused by protracted antibiotic use, they suggest.

Source:

https://vector.childrenshospital.org/2018/06/microbiome-metabolism-immune-system/

Tagged with:

About author

Related Articles