fiber intake Archives - Amazing Health Advances

High-Fiber Diet Associated With Improved Progression-Free Survival and Response to Immunotherapy in Melanoma Patients

AHA Publisher — Mon, 27 Dec 2021 08:00:57 +0000

University of Texas M. D. Anderson Cancer Center via Newswise – HOUSTON ― Patients with melanoma who reported eating more fiber-rich foods when they began immunotherapy treatment survived longer without cancer growth than patients with insufficient dietary fiber intake, according to new research from The University of Texas MD Anderson Cancer Center published today in Science. The benefit was most noticeable in patients who did not take commercially available probiotic supplements. Parallel pre-clinical studies supported the observational findings. “Research from our team and others has shown that gut microbes impact response to immunotherapy treatment, but the role of diet and probiotic supplements has not been well studied,” said co-senior author Jennifer Wargo, M.D., professor of Genomic Medicine and Surgical Oncology. “Our study sheds light on the potential effects of a patient’s diet and supplement use when starting treatment with immune checkpoint blockade. These results provide further support for clinical trials to modulate the microbiome with the goal of improving cancer outcomes using dietary and other strategies.” Patients who reported eating more fruits, vegetables, legumes and whole grains met the study threshold for sufficient fiber intake. The 37 patients with sufficient fiber intake had improved progression-free survival (median not reached) compared to the 91 patients with insufficient fiber intake (median 13 months). Every five-gram increase of daily fiber intake was associated with a 30% lower risk of cancer progression or death. When the patients were further grouped according to high- or low-fiber diet and commercially-available probiotic supplement use, response to immunotherapy was seen in 18 of 22 patients (82%) who reported both sufficient fiber intake and no probiotic use, compared to the response seen in 60 of 101 (59%) patients who either reported insufficient fiber intake or probiotic use. Response was defined as complete or partial complete or partial tumor shrinkage or stable disease for at least six months. Probiotic use alone was not associated with a significant difference in progression-free survival or odds of response to immunotherapy. “Dietary fiber is important for gut health, just as it’s important for overall health, and the two things are very tightly intertwined,” said co-senior author Carrie Daniel-MacDougall, Ph.D., associate professor of Epidemiology. “In this study, we saw that dietary fiber also may be important to cancer treatment, which brings us to a point where we can design interventional studies to answer the questions that patients really want answered: ‘Does what I eat now matter and could it impact my treatment outcome?’ We’re united in working to find answers for our patients.” Differences in Gut Microbiota and Pre-Clinical Models The study began with analyzing the gut microbiome profiles of 438 melanoma patients, 321 of whom had late-stage disease and were treated with systemic therapy, and 293 of whom had an evaluable response to treatment over follow-up. The majority of these patients (87%) received immune checkpoint blockade, most commonly PD-1 inhibitors. A total of 158 patients also completed a lifestyle survey of antibiotics and probiotics usage; of these, 128 completed a dietary questionnaire as they began immune checkpoint therapy. The research team reinforced their prior findings, which showed a higher abundance of Ruminococcaceae and Faecalibacterium prausnitzii – well-known and potentially beneficial bacteria involved in the digestion of fiber or starch – in patients who responded to immunotherapy. In contrast to the previous findings, overall diversity of gut bacteria was not associated with response to immunotherapy, potentially due to the larger size of this patient cohort. The researchers also tested higher versus lower fiber diets and probiotic use in several preclinical melanoma models to shed light on the potential mechanisms behind the observational findings from the patient cohorts. In multiple models, probiotic use was associated with impaired response to immune checkpoint blockade, larger tumors, lower gut microbiome diversity and less cytotoxic T cells in the tumor microenvironment. A high-fiber diet was associated with slower tumor growth and significantly higher frequency of CD4+ T cells in pre-clinical models treated with PD-1 inhibitors. Clinical Trial to Build on Findings, Test Effect of Dietary Intervention Based on the early study findings, a randomized clinical trial (NCT04645680), led by co-first author Jennifer McQuade, M.D., assistant professor of Melanoma Medical Oncology, will examine how whole-food-based diets with varying fiber content affect the microbiome and immune response. The study is currently enrolling patients with stage III-IV melanoma who are receiving immunotherapy. “Our research teams within the Program for Innovative Microbiome and Translational Research (PRIME-TR) and Bionutrition Research Core at MD Anderson are collectively working to transform cancer therapy by modifying the microbiome,” Wargo said. “We’re grateful to the patients and families who have participated in our research and are hopeful that this work will ultimately provide evidence-based guidance to help patients take control of their own diets to improve their odds against cancer.” To read the original article click here.

The post High-Fiber Diet Associated With Improved Progression-Free Survival and Response to Immunotherapy in Melanoma Patients appeared first on Amazing Health Advances.

Gut Bacteria and Flavonoid-Rich Foods Are Linked and Improve Blood Pressure Levels

AHA Publisher — Tue, 24 Aug 2021 07:00:10 +0000

American Heart Association (AHA) via Newswise – Flavonoid-rich foods, including berries, apples, pears and wine, appear to have a positive effect on blood pressure levels, an association that is partially explained by characteristics of the gut microbiome, according to new research published today in Hypertension, an American Heart Association journal. “Our gut microbiome plays a key role in metabolizing flavonoids to enhance their cardioprotective effects, and this study provides evidence to suggest these blood pressure-lowering effects are achievable with simple changes to the daily diet,” said lead investigator of the study Aedín Cassidy, Ph.D., chair and professor in nutrition and preventive medicine at the Institute for Global Food Security at Queen’s University in Belfast, Northern Ireland. Flavonoids are compounds found naturally in fruits, vegetables and plant-based foods such as tea, chocolate and wine, and have been shown in previous research to offer a variety of health benefits to the body. Flavonoids are broken down by the body’s gut microbiome—the bacteria found in the digestive tract. Recent studies found a link between gut microbiota, the microorganisms in the human digestive tract, and cardiovascular disease (CVD), which is the leading cause of death worldwide. Gut microbiota is highly variable between individuals, and there are reported differences in gut microbial compositions among people with and without CVD. With increased research suggesting flavonoids may reduce heart disease risk, this study assessed the role of the gut microbiome on the process. Researchers examined the association between eating flavonoid-rich foods with blood pressure and gut microbiome diversity. The study also investigated how much variance within the gut microbiome could explain the association between intake of flavonoid-rich foods and blood pressure. A group of 904 adults between the ages of 25 and 82, 57% men from Germany’s PopGen biobank were recruited for this study. (The PopGen biobank includes participants from a network of seven biobanks in Northern Germany.) Researchers evaluated the participants’ food intake, gut microbiome and blood pressure levels together with other clinical and molecular phenotyping at regular follow-up examinations. Participants’ intake of flavonoid-rich foods during the previous year was calculated from a self-reported food questionnaire detailing the frequency and quantity eaten of 112 foods. Flavonoid values were assigned to foods according to United States Department of Agriculture data on flavonoid content in food. Gut microbiome for participants was assessed by fecal bacterial DNA extracted from stool samples. After an overnight fast, participants’ blood pressure levels were measured three times in three-minute intervals after an initial five-minute rest period. Researchers also collected participants’ lifestyle information, including sex, age, smoking status, medication use and physical activity, as well as family history of coronary artery disease, the number of daily calories and fiber consumed, and each participant’s height and weight was measured to calculate BMI (body mass index). The analysis of regular flavonoid intake with gut microbiome and blood pressure levels found: Study participants who had the highest intake of flavonoid-rich foods, including berries, red wine, apples and pears, had lower systolic blood pressure levels, as well as greater diversity in their gut microbiome than the participants who consumed the lowest levels of flavonoid-rich foods. Up to 15.2% of the association between flavonoid-rich foods and systolic blood pressure could be explained by the diversity found in participants’ gut microbiome. Eating 1.6 servings of berries per day (one serving equals 80 grams, or 1 cup) was associated with an average reduction in systolic blood pressure levels of 4.1 mm Hg, and about 12% of the association was explained by gut microbiome factors. Drinking 2.8 glasses (125 ml of wine per glass) of red wine a week was associated with an average of 3.7 mm Hg lower systolic blood pressure level, of which 15% could be explained by the gut microbiome. “Our findings indicate future trials should look at participants according to metabolic profile in order to more accurately study the roles of metabolism and the gut microbiome in regulating the effects of flavonoids on blood pressure,” said Cassidy. “A better understanding of the highly individual variability of flavonoid metabolism could very well explain why some people have greater cardiovascular protection benefits from flavonoid-rich foods than others.” While this study suggests potential benefits to consuming red wine, the American Heart Association suggests that if you don’t drink alcohol already, you shouldn’t start. If you do drink, talk with your doctor about the benefits and risks of consuming alcohol in moderation. According to a statement on dietary health by the American Heart Association, alcohol intake can be a component of a healthy diet if consumed in moderation (no more than one alcoholic drink per day for women and 2 alcohol drinks per day for men) and only by nonpregnant women and adults when there is no risk to existing health conditions, medication-alcohol interaction, or personal safety and work situations. The authors note that participants for the study were from the general population, and the participants were unaware of the hypothesis. However, residual or unmeasured confounding factors (such as other health conditions or genetics) can lead to bias, thus these findings cannot prove a direct cause and effect, although the researchers did conduct a detailed adjustment in their analyses for a wide range of diet and lifestyle factors. The authors noted the focus of this study was on specific foods rich in flavonoids, not all food and beverages with flavonoids. To read the original article click here.

The post Gut Bacteria and Flavonoid-Rich Foods Are Linked and Improve Blood Pressure Levels appeared first on Amazing Health Advances.