About

Diana N Obanda is an Assistant Professor in the Department of Nutrition & Food Science at the University of Maryland. Her research focuses on nutritional biochemistry, specifically the function of nutrients at the cellular and molecular levels, and the physiological mechanisms of various nutrition-related processes. She investigates the influence of food and medicinal plant compounds with bioactivities targeting obesity mechanisms, gut microbiota composition, and gut immune function. Her work includes elucidating mechanisms responsible for altered gene expression in skeletal muscle, adipose tissue, and intestinal tissue, and their overall impact on obesity and insulin resistance. Additionally, she explores functional foods as interventions for obesity-related gut microbiota dysbiosis, insulin resistance, and inflammation.

Research topics

• Biology
• Traditional medicine
• Botany
• Biochemistry
• Medicine
• Food science
• Microbiology
• Internal medicine
• Pharmacology

Selected publications

• Impacts of the vegetable Urtica dioica on the intestinal T and B cell phenotype and macronutrient absorption in C57BL/6J mice with diet-induced obesity

  The Journal of Nutritional Biochemistry · 2024-03-30 · 1 citations

  articleSenior authorCorresponding
  PublisherDOI

• Fermenting kale ( <i>Brassica oleracea</i> L.) enhances its functional food properties by increasing accessibility of key phytochemicals and reducing antinutritional factors

  Food Science & Nutrition · 2024-05-06 · 14 citations

  articleOpen accessSenior authorCorresponding

  Abstract The properties of kale as a functional food are well established. We sought to determine how fermentation further enhances these properties. We tested different fermentation conditions: (i) spontaneous fermentation with naturally occurring bacteria, (ii) spontaneous fermentation with 2% salt, (iii) Lactococcus lactis , (iv) Lactobacillus acidophilus , (v) mixture of L. lactis and L. acidophilus , (vi) mixture of L. lactis , L. acidophilus , and Clostridium butyricum. We quantified selected bioactive components using high‐performance liquid chromatography (HPLC) and antinutritional factors using a gravimetric method and spectrophotometry. We then determined (i) the antioxidant capacity of the vegetable, (ii) anti‐inflammation capacity, and (iii) the surface microbiota composition by 16S sequencing. All fermentation methods imparted some benefits. However, fermentation with mixed culture of L. lactis and L. acidophilus was most effective in increasing polyphenols and sulforaphane accessibility, increasing antioxidant activity, and reducing antinutritional factors. Specifically, fermentation with L. lactis and L. acidophilus increased total polyphenols from 8.5 to 10.7 mgGAE/g (milligrams of gallium acid equivalent per gram) and sulforaphane from 960.8 to 1777 μg/g (microgram per gram) but decreased the antinutritional factors oxalate and tannin. Total oxalate was reduced by 49%, while tannin was reduced by 55%–65%. The antioxidant capacity was enhanced but not the anti‐inflammation potential. Both unfermented and fermented kale protected equally against lipopolysaccharide (LPS)‐induced inflammation in RAW 264.7 macrophages and prevented increases in inducible nitric oxide synthase (iNOS), tumor necrosis factor‐alpha (TNF‐α), interleukin‐1 beta (IL‐1β), and interleukin‐6 messenger RNA (IL‐6 mRNA) expression by 84.3%, 62%, 68%, and 85.5%, respectively. Unfermented and naturally fermented kale had high proportions of sulfur reducing Desulfubrio and Proteobacteria usually associated with inflammation. Fermenting with L. lactis and/or L. acidophilus changed the bacterial proportions, reducing the Proteobacteria while increasing the genera Lactobacilli and Lactococcus. In summary, fermentation enhances the well‐known beneficial impacts of kale. Fermentation with mixed cultures of L. lactis and L. acidophilus imparts higher benefits compared to the single cultures or fermentation with native bacteria present in the vegetable.

  PublisherOA PDFDOI

• Three Clostridium Species With Potential Health Imparting Properties: In Vitro Screening and Probiotic Assessment-A Proposal

  Current Developments in Nutrition · 2024-06-29 · 1 citations

  articleOpen accessSenior author

  Objectives:In two previous studies in obesity models (Sprague Dawley CD rats and C57BL6 mice) we have shown that a higher representation of genus Clostridium sensu stricto (Cluster I) correlates with lower body weight; resistance to diet induced obesity, inflammation, and insulin resistance.Rodents that remained lean and insulin sensitive despite exposure to an obesogenic high fat diet had 3-50X higher amounts of Clostridium compared to those that easily developed obesity.Among species identified were C. disporicum, C. celatum, and C. vincentii.We hypothesize that metabolites of these bacteria impact lipid metabolism and/or inflammation pathways to protect against diet induced obesity.Being strict anaerobes, we explored use of spores to exploit their potential as probiotics.Methods: We cultured the bacteria, allowed sporulation to occur, quantified spores and subjected them to air (oxygen) for 21 days, simulated gastric acid, and bile acids for 4 hours and different temperatures up to 100 C, before exposing them to favorable anaerobic conditions to check for resilience and ability to germinate and form colonies on agar plates.In ongoing in vitro tests we aim at (i) testing antibacterial activity (potential to inhibit the growth of pathogenic bacteria), (ii) triglyceridelowering capacity, bile salt hydrolase activity and alpha-glucosidase inhibiting capacity all as a measure that can reduce fat or glucose absorption in cases of excesses in the diet, (iii) hemolytic activity and antibiotic susceptibility to ensure the safety as probiotics (v) will treat Caco-2 cells with bacteria cell free supernatant and screen the Toll-Like Receptor (TLRs) signaling pathway and inflammation pathways using the RT 2 profiler PCR Array.Results: Spores from all 3 species survived exposure up to 70oc.After exposure to air/oxygen survival rates were 68.2%, 55.7% and 49.5% for C. celatum, C. disporicum and C. vincentii respectively.Survival after exposure to gastric juice was 86.7%, 65.0% 25.6% for C. celatum, C. disporicum and C. vincentii respectively.Survival after exposure to bile acids was 57.8%, 65% and 50.7% for C. celatum, C. disporicum and C. vincentii respectively.Conclusions: The resilience of the spores to environmental and gut conditions demonstrates potential for successful oral administration and colonization of the three bacteria spores in the mammalian lower gut.The in vitro tests on potential health benefits are ongoing.

  PublisherOA PDFDOI

• The Vegetable Kale Prevents Pro-inflammatory Lipopolysaccharide Effects by Blocking Its Binding to TLR4-MD2 and Increasing the Activity of Intestinal Alkaline Phosphatase

  Current Developments in Nutrition · 2024-06-29

  articleOpen accessSenior author
  PublisherOA PDFDOI

• The Vegetable Urtica Dioca Protects Against Diet-Induced Obesity Through Pathways That Are Both Dependent And Independent of The Gut Microbiota

  Current Developments in Nutrition · 2024-06-29

  articleOpen accessSenior author

  Objectives: Diet-induced obesity is associated with several factors which include the gut microbiota and associated metabolites. We have previously shown that through mechanisms that involve gut microbiota function the vegetable Urtica dioca (UT) attenuates fat accumulation and insulin resistance due to a high-fat (HF) diet. In this follow-up study, we sought to determine whether inclusion of UT in an HF diet would be protective in the absence of gut microbiota. We hypothesized that UT imparts beneficial effects that are dependent and independent of the microbiota.

  PublisherDOI

• Resistance to Diet Induced Visceral Fat Accumulation in C57BL/6NTac Mice Is Associated with an Enriched Lactococcus in the Gut Microbiota and the Phenotype of Immune B Cells in Intestine and Adipose Tissue

  Microorganisms · 2023-08-25 · 4 citations

  articleOpen accessSenior authorCorresponding

  Humans and rodents exhibit a divergent obesity phenotype where not all individuals exposed to a high calorie diet become obese. We hypothesized that in C57BL/6NTac mice, despite a shared genetic background and diet, variations in individual gut microbiota function, immune cell phenotype in the intestine and adipose determine predisposition to obesity. From a larger colony fed a high-fat (HF) diet (60% fat), we obtained twenty-four 18–22-week-old C57BL/6NTac mice. Twelve had responded to the diet, had higher body weight and were termed obese prone (OP). The other 12 had retained a lean frame and were termed obese resistant (OR). We singly housed them for three weeks, monitored food intake and determined insulin resistance, fat accumulation, and small intestinal and fecal gut microbial community membership and structure. From the lamina propria and adipose tissue, we determined the population of total and specific subsets of T and B cells. The OP mice with higher fat accumulation and insulin resistance harbored microbial communities with enhanced capacity for processing dietary sugars, lower alpha diversity, greater abundance of Lactobacilli and low abundance of Clostridia and Desulfobacterota. The OR with less fat accumulation retained insulin sensitivity and harbored microbial communities with enhanced capacity for processing and synthesizing amino acids and higher diversity and greater abundance of Lactococcus, Desulfobacterota and class Clostridia. The B cell phenotype in the lamina propria and mesenteric adipose tissue of OR mice was characterized by a higher population of IgA+ cells and B1b IgM+ cells, respectively, compared to the OP. We conclude that variable responses to the HF diet are associated with the function of individuals’ gut microbiota and immune responses in the lamina propria and adipose tissue.

  PublisherOA PDFDOI

• P03-019-23 Urtica dioica Whole Vegetable Attenuates Diet-Induced Obesity via Mechanisms Involving Fat Absorption and Immune Cell Function in the Small Intestines

  Current Developments in Nutrition · 2023-07-01

  articleOpen access
  PublisherDOI

• OR22-07-23 Kale Vegetable Attenuates Colitis by Abating the Proliferation of Lipopolysaccharide-Producing Gut Bacteria and Augmenting Gut Barrier Integrity

  Current Developments in Nutrition · 2023-07-01

  articleOpen access
  PublisherDOI

• P06-046-23 Fermentation of Kale (Brassica oleracea var. sabellica) Vegetable Enhances Its Properties as a Functional Food

  Current Developments in Nutrition · 2023-07-01 · 1 citations

  articleOpen access
  PublisherDOI

• Could a nettle a day keep the doctor away?

  2023-01-01

  articleOpen access1st authorCorresponding

  When out for a walk in summer, nettles are little more than a nuisance, their sharply serrated leaves warning you to steer clear of their venomous hairs and hardly inviting the thought of putting them in your mouth.Yet they are edible, and indeed are eaten in many cultures around the world.So what is it about nettles that makes it worth getting past the stings?Dr Diana Obanda, Assistant Professor in Nutrition and Food Science, is on the case.Her team at the University of Maryland is using mice and cultured cells to try to understand how Urtica dioica contributes to a healthy diet.The evidence is pointing at nettles' ability to protect us from Nettles are known for their sting, but research by Dr Diana Obanda at the University of Maryland in the US suggests that eating them could strengthen our gut and protect us from obesity.

  PublisherOA PDFDOI

Frequent coauthors

• William T. Cefalu

  20 shared

• Samnhita Raychaudhuri

  13 shared

• Si Fan

  13 shared

• Yongmei Yu

  12 shared

• David Ribnicky

  Rutgers, The State University of New Jersey

  11 shared

• Opeyemi Ogedengbe

  10 shared

• Md Shahinozzaman

  University of Maryland, College Park

  8 shared

• Jacqueline M. Stephens

  Pennington Biomedical Research Center

  8 shared

Education

• PhD, Nutrition & Food Science

  Louisiana State University

  2017

• PhD, Environmental Sciences

  Louisiana State University and Agricultural and Mechanical College

  2008

• MSc, Environmental Sciences

  Louisiana State University and Agricultural and Mechanical College

  2007

• BSc

  Moi University

  1997