“We know eating avocados helps you feel full and reduces blood cholesterol concentration, but we did not know how it influences the gut microbes, and the metabolites the microbes produce,” says Sharon Thompson, graduate student in the Division of Nutritional Sciences at U of I and lead author on the paper, published in the Journal of Nutrition.

The researchers found that people who ate avocado every day as part of a meal had a greater abundance of gut microbes that break down fiber and produce metabolites that support gut health. They also had greater microbial diversity compared to people who did not receive the avocado meals in the study.

“Microbial metabolites are compounds the microbes produce that influence health,” Thompson says. “Avocado consumption reduced bile acids and increased short chain fatty acids. These changes correlate with beneficial health outcomes.”

The study included 163 adults between 25 and 45 years of age with overweight or obesity — defined as a BMI of at least 25 kg/m2 — but otherwise healthy. They received one meal per day to consume as a replacement for either breakfast, lunch, or dinner. One group consumed an avocado with each meal, while the control group consumed a similar meal but without the avocado. The participants provided blood, urine, and fecal samples throughout the 12-week study. They also reported how much of the provided meals they consumed, and every four weeks recorded everything they ate.

While other research on avocado consumption has focused on weight loss, participants in this study were not advised to restrict or change what they ate. Instead they consumed their normal diets with the exception of replacing one meal per day with the meal the researchers provided.

The purpose of this study was to explore the effects of avocado consumption on the gastrointestinal microbiota, says Hannah Holscher, assistant professor of nutrition in the Department of Food Science and Human Nutrition at U of I and senior author of the study.

“Our goal was to test the hypothesis that the fats and the fiber in avocados positively affect the gut microbiota. We also wanted to explore the relationships between gut microbes and health outcomes,” Holscher says.

Avocados are rich in fat; however, the researchers found that while the avocado group consumed slightly more calories than the control group, slightly more fat was excreted in their stool.

“Greater fat excretion means the research participants were absorbing less energy from the foods that they were eating. This was likely because of reductions in bile acids, which are molecules our digestion system secretes that allow us to absorb fat. We found that the amount of bile acids in stool was lower and the amount of fat in the stool was higher in the avocado group,” Holscher explains.

Different types of fats have differential effects on the microbiome. The fats in avocados are monounsaturated, which are heart-healthy fats.

Soluble fiber content is also very important, Holscher notes. A medium avocado provides around 12 grams of fiber, which goes a long way toward meeting the recommended amount of 28 to 34 grams of fiber per day.

“Less than 5% of Americans eat enough fiber. Most people consume around 12 to 16 grams of fiber per day. Thus, incorporating avocados in your diet can help get you closer to meeting the fiber recommendation,” she notes.

Eating fiber isn’t just good for us; it’s important for the microbiome, too, Holscher states. “We can’t break down dietary fibers, but certain gut microbes can. When we consume dietary fiber, it’s a win-win for gut microbes and for us.”

Holscher’s research lab specializes in dietary modulation of the microbiome and its connections to health. “Just like we think about heart-healthy meals, we need to also be thinking about gut healthy meals and how to feed the microbiota,” she explains.

Avocado is an energy-dense food, but it is also nutrient dense, and it contains important micronutrients that Americans don’t eat enough of, like potassium and fiber.

“It’s just a really nicely packaged fruit that contains nutrients that are important for health. Our work shows we can add benefits to gut health to that list,” Holscher says.

The paper, “Avocado consumption alters gastrointestinal bacteria abundance and microbial metabolite concentrations among adults with overweight or obesity: a randomized controlled trial” is published in the Journal of Nutrition.

Authors are Sharon Thompson, Melisa Bailey, Andrew Taylor, Jennifer Kaczmarek, Annemarie Mysonhimer, Caitlyn Edwards, Ginger Reeser, Nicholas Burd, Naiman Khan, and Hannah Holscher.

Funding for the research was provided by the Hass Avocado Board and the USDA National Institute of Food and Agriculture, Hatch project 1009249. Sharon Thompson was supported by the USDA National Institute of Food and Agriculture AFRI Predoctoral Fellowship, project 2018-07785, and the Illinois College of ACES Jonathan Baldwin Turner Fellowship. Jennifer Kaczmarek was supported by a Division of Nutrition Sciences Excellence Fellowship. Andrew Taylor was supported by a Department of Food Science and Human Nutrition Fellowship. The Division of Nutritional Sciences provided seed funding through the Margin of Excellence endowment.

The Division of Nutritional Sciences and the Department of Food Science and Human Nutrition are in the College of Agricultural, Consumer and Environmental Sciences, University of Illinois.

Inspired by a similar program in South Africa, PhD student and senior research fellow Tista Ghosh, along with Dr Samrat Mondol (WII) and Amit Sharma (WWF India), collected dung from 749 rhinoceros to gather vital genetic information. By analysing dung for traces of population specific genetic signals, a genetic baseline was created for rhinoceros across India and 406 unique individuals were identified.

Microsatellite markers are present in nuclear DNA, similar to a fingerprint, where each individual has its own unique genetic signature. The use of 14 markers helps to identify individuals from dung data based on unique individual rhino’s signature.

By comparing seized rhino horn samples to these specific genetic signals, the researchers could trace the rhino back to its breeding population, thus identifying trade routes and pinpointing poaching hotspots, which are notoriously difficult for traditional law enforcement to track.

“Having an allele frequency map aids in pinpointing the location of the orphan seized rhino sample to its breeding population based on genetic signatures,” commented Tista Ghosh.

The forensics team at WII were also able to match a suspected poached carcass from a protected area to a seized horn found elsewhere along the trade route in India. Occasionally, they had as little to work with as blood-stained soil, pebbles or a bullet to perform DNA profiling.

These results display the powerful abilities which this microsatellite panel has for tackling wildlife crime and providing valuable insights to the forest department. Furthermore, individual DNA matching assists in court prosecutions by providing concrete scientific evidence regarding the poaching of wild rhino, native to India.

On the significance of this method, Tista said: “Many times the seized rhino body parts are found after a long time of poaching incidence as a result of which it becomes difficult to pinpoint the location of the crime. Thus, it is important to locate such networks and have law enforcement resulting in breaking the chain of trading.”

India’s current population of greater one-horned rhinoceros’ is relatively small, at approximately 3,500 rhino individuals. Using statistical probabilities, the team calculated that 14 microsatellite markers were sufficient to be able to do individual matching across the whole range of the population.

In addition, the researchers are keen to collaborate with Nepal field teams to extend this work to the second strong hold of greater one-horned rhinoceros.

However, in the field of wildlife forensics, there are severe limitations due to the poor quality of samples, and circumstances when data could not be generated using microsatellite only. In those scenarios Tista said, of these exciting developments, “We are planning to do a mitochondrial DNA screening to look for park/state specific genetic markers and combine that data with our existing database to avoid such situations.”

Further the RhODIS-India marker panel is still in the process of developing an ‘allelic ladder’ (reference point) for comparisons with other laboratories. When this becomes available, this will foster greater collaboration between the global wildlife forensics community. In order to increase the size of the database, plans are already in place to carry out wider sampling across the Indian rhino’s range.

Tista Ghosh’s talk will be available on-demand from the 14th — 18th of December 2020 at the Festival of Ecology. The selection procedure of a 14-microsatellite panel and its application in curbing rhino poaching in India is currently under review in a peer reviewed scientific journal. This online conference will bring together 1,400 ecologists from than 50 countries to discuss the most recent breakthroughs in ecology.

This research is managed by the Wildlife Institute of India is led by the MOEFC&C (environment ministry) in India in collaboration with WWF India and the Wildlife Institute of India.

“A deeper understanding of the immunobiology of breast cancer is critical to the success in harnessing immunotherapeutic approaches to improve breast cancer survival,” said Paula Bos, Ph.D., member of the Cancer Biology research program at VCU Massey Cancer Center and assistant professor in the Department of Pathology at the VCU School of Medicine.

New research findings from Bos, published in Cell Reports, identified a type of immune cells that acts as a major driver of breast cancer growth by preventing the accumulation of a specific protein that induces anti-tumor responses. This new knowledge could be utilized for the development of novel immunotherapeutic approaches to treat the disease.

Regulatory T cells (Treg cells) are a special class of immune cells that possess a unique ability to suppress the function of other immune cells. This function serves to protect the organism from overreacting to certain molecules created within the body; however, in many cases it subdues the immune system’s ability to attack cancer cells. Therefore, Treg cells are often abundant in solid tumors, particularly breast cancers, and are commonly associated with worse outcomes.

In previous research, Bos demonstrated that targeting Treg cells in breast cancer models significantly reduced tumor growth and metastasis; however, it remained unclear on a molecular level why this tumor reduction was happening.

There is a specific protein called interferon gamma (IFN-g) that has powerful anti-tumor properties, including the activation of macrophages, which are cells that can initiate inflammation and prevent cancer growth.

Bos’ latest study suggests that Treg cells suppress IFN-g production by CD4 T lymphocytes (a type of white blood cells), further instigating disease progression. After analyzing breast cancer models in which Treg cells had been targeted and destroyed, Bos discovered an increased presence of IFN-g and functional reprogramming of macrophages into tumor-fighting cells.

“Additionally, we demonstrated better overall survival in human cancers with similar genetic patterns to those observed in mice with breast cancer whose Treg cells were eliminated,” Bos said.

This research is the first of its kind to study the mechanistic function of Treg cells in breast cancer.

Bos said these findings validate the potential for adoptive transfer therapeutics using macrophages programmed with the IFN-g protein to effectively treat breast cancer. Adoptive transfer refers to the process of transferring external cells into a patient to improve immune function or response.

“Our work raises the possibility that white blood cells can be extracted from cancer patients, reprogrammed outside of their body through brief exposure to the IFN-g protein and re-infused back into the patient, contributing to the generation of anti-tumor responses,” Bos said.

Bos is currently studying the function of Treg cells in metastatic cancer and plans to design follow-up studies testing the utilization of IFN-g as an adoptive transfer therapeutic agent in cancer mouse models.

Bos collaborated on this research with Mikhail Dozmorov, Ph.D., member of the Cancer Biology research program at Massey; Amy Olex, M.S., of the VCU C. Kenneth and Dianne Wright Center for Clinical and Translational Research; and Nicholas Clark, Ph.D., James deLigio, Comfort Effi, Leandro Martinez, and Steven Murdock of the VCU School of Medicine.

Story Source:

Materials provided by Virginia Commonwealth University. Original written by Blake Belden. Note: Content may be edited for style and length.

Under climate change, there’s a growing interest in assessing whether trees and other species can keep pace with changing temperatures and rainfall, shifting where they are found, also known as their ranges, to track their suitable climates. To test this, a University of Maine-led research team studied the current ranges of hundreds of North American trees and shrubs, assessing the degree to which species are growing in all of the places that are climatically suitable. Researchers found evidence of widespread “underfilling” of these potential climatic habitats — only 50% on average — which could mean that trees already have disadvantage as the world continues to warm.

Benjamin Seliger, a then UMaine Ph.D. student with the Climate Change Institute, spearheaded the study with his doctoral adviser, Jacquelyn Gill, a UMaine associate professor of paleoecology and plant ecology. Brain McGill, a UMaine professor of biological sciences, and Jens-Christian Svenning, a macroecologist and biogeographer from Aarhus University in Denmark also contributed.

The team used species distribution models to assess the degree to which 447 North American trees’ and shrubs’ “fill” their potential climatic ranges by comparing regions that are climatically suitable, known as potential ranges, against where trees are actually found, or their realized ranges.

The Journal of Biogeography published the team’s research paper for the study.

Seliger, now a postdoctoral researcher at the Center of Geospatial Analytics at North Carolina State University, and co-authors discovered a significant difference between where the trees they studied could grow, and where they actually grow, also known as range filling. The average range filling value across all 447 species equalled 48.6%, indicating that on average, trees are not found in about half of the areas that are climatically suitable for them, according to researchers.

“We found tree ranges are more limited by non-climatic factors than expected, suggesting trees may not simply track warming climates.” Seliger says.

Species distribution models (SDMs) are a common tool to predict how climate change will affect biodiversity and the future ranges of plants and animals. Various studies, including the one from the UMaine-led group, however, caution that because this tool assumes that species live in all areas that are climatically suitable, known as experiencing climatic equilibrium, it may not provide an accurate prediction of where species will be found in the future.

An SDM relies on what has been considered a foundational principle, “that geographic ranges generally appear to be in equilibrium with contemporary climate,” according to researchers. Growing evidence suggests otherwise for many species, which experience climatic disequilibrium.

Seliger and his team found that North American trees and shrubs with large ranges tended to show much stronger evidence of climatic equilibrium, meaning they had high range filling. Small-ranged species, however, had much lower range filling overall, performing worse than predicted by a null model. According to researchers, that means small-ranged tree species, including many rare trees and species the International Union for the Conservation of Nature (IUCN) lists as vulnerable, will face additional challenges as they try to track their climates into the future.

The group also found that small-rage species may be more limited by nonclimatic influences, such as soils or pathogens. Conservation efforts for these plants and animals, therefore, should “account for a complex interplay of factors in addition to climate when preparing for the next century of global change,” according to researchers.

Their findings support a growing body of evidence that for a climatic disequilibrium among various flora. As to what causes the disequilibrium could be due to two factors, according to researchers: dispersal lags that date back to the time when glaciers covered large portions of North American 21,000 years ago, or by non-climatic factors that may influence ranges more than previously appreciated, such as soil, competition with other plants, or symbiosis.

“It’s been thought that if you zoom out to the scale of North America, climate was the most important factor in determining where species would be found. This study reveals some striking gaps in our knowledge; even at the scale of an entire continent, soils or other plants and animals may be playing an important role too. We used to think those were more important at the more local scale — think of how the trees might change across two areas of your favorite park,” Gill says. “All of this means that when it comes to plants, our predictive tools need to get a lot more sophisticated, if they’re going to be useful for conservation.”