Progress 05/01/24 to 04/30/25
Outputs
Target Audience:The project hypothesizes that whole food fibers are better for gut health than isolated added fibers. If shown to be true, our target audience will be a wide range of consumers who consume whole and processed foods where whole food fiber concentrates can be added. The food industry is a target audience for this research as they could incorporate whole food fiber concentrates and mixtures, determined from this project, in their food products. We interact at least twice a year with industry members of the Whistler Center for Carbohydrate Research and disseminate results. Another target audience are researchers and health professionals that will be informed of advancements in this area. In this period, we had a Purdue press release for the project at https://ag.purdue.edu/news/2024/03/promoting-beneficial-gut-microbes-with-whole-food-dietary-fiber.html. Changes/Problems: Hiring Delays: Six month delay in staff recruitment postponed lab start to January2024. Protocol Optimization: Required extensive trials to adapt enzymatic digestion across diverse food matrices for the goal of not disrupting the native whole food matrix. What opportunities for training and professional development has the project provided?We have trained two visiting scholars, one undergraduate, and one graduate student in fiber isolation procedures and in vitro fecal fermentations, short chain fatty acids analysis and bacterial DNA extraction and sequencing. How have the results been disseminated to communities of interest?Our findings ("Whole food fibers for support of key gut bacteria for human health") have been shared with relevant scientific and industry communities through the following poster presentations: Purdue Applied Microbiome Sciences (PAMS) (May,2024) Purdue Fermentation Frenzy (January,2025) Won Fermentation Frenzi Poster Competition Indiana Nutrition for Health Research Showcase (February,2025) Purdue College of Agriculture & College of Engineering Joint Poster Session & Networking Gathering (March,2025) Purdue Food Science Industrial Associates Poster Session (April,2025) Purdue Whistler Center for Carbohydrate Research Annual Meeting Poster Session (April, 2025) Midwest Microbiome Symposium, Ohio State University, Columbus, OH (May,2025) Presented at USDA NIFA 2025 Food and Human Health Meeting, Purdue University (May 2025). Each session provided an opportunity to engage with experts in microbiome science, nutrition, and industrial applications--getting feedback to refine our protocols and guide future clinical evaluations. What do you plan to do during the next reporting period to accomplish the goals?During the next reporting period, we will complete fecal fermentations for the total 20 whole food fiber treatments to complete our individual fiber in vitro screening. This will include SCFA quantification and 16S rRNA sequencing to study the enrichment of Clostridium clusters IV and XIVa. Subsequently, with the previous results, we will optimize and validate five-component fiber mixtures by assessing their ability to stimulate SCFA production and shift microbial community composition. The most effective formulations will be selected for the clinical trial, and scale-up and product development. Using food science formulation strategies, we will convert the optimized fiber mixture into clinical-ready formats such as powdered sachets. This phase will involve testing excipients for rapid dispersion of insoluble fiber, improving taste and mouthfeel, and ensuring shelf-life stability. We aim to establish a scalable, food-grade manufacturing process that meets clinical and regulatory standards. Preparations will also begin for the human crossover trial planned for January 2026. We will recruit participants, finalize IRB approvals, and ensure that the clinical-grade fiber blend is produced and packaged for trial use. By the end of this period, we anticipate completing all in vitro fermentations and identifying a fiber blend that consistently enhances Clostridium clusters IV and XIVa and increases butyrate levels. The selected formulation will be produced at a food-grade facility, with demonstrated in vitro efficacy and readiness for clinical evaluation. We also expect preliminary evidence of improved gut barrier integrity and reduced inflammatory markers in vivo.
Impacts
What was accomplished under these goals?
Project activities began in January 2024 following a six-month delay in hiring. The research team initiated lab operations by preparing twenty whole-food samples, which were freeze-dried, milled to a particle size of 250-600µm, and enzymatically purified to remove starch and protein. Two visiting scholars were trained to perform these standardized extractions to ensure consistency across all samples. The visiting scholar, who later in the year continued in the program as a graduate student, led the optimization of the enzymatic digestion protocol using food-grade enzymes. A total of seven starch and three protein digestion conditions were screened independently. The final optimized method involved two sequential additions of α-amylase (SIGMA A4862; 33µL/g) at 90°C, followed by amyloglucosidase (Lallemand; 10µL/g) at 60°C. Protein digestion was carried out at pH 8.0 using a balanced mix of Novozyme proteases (P1, P2, P3; 132µL/g) at 55°C for three hours. This protocol achieved over 99.9% starch removal and 46.9-65.8% protein reduction in cassava, potato, bean, and chickpea fibers. The importance of the optimized fiber isolation protocol is two-fold, first, to obtain a near-pure fiber materials that are food-grade for the upcoming clinical trial and, second, to have a protocol in place that potentially could be scaled to produce whole food fiber mixtures for a commercial market. Following digestion, an ultrafiltration unit was acquired, with funding support from Purdue's Whistler Center for Carbohydrate Research, and set up to remove residual digestion components and concentrate fiber fractions. After several trial runs, operating parameters were finalized for processing all 20 whole-food fiber samples. Preliminary in vitro fermentations were conducted using four purified fibers--potato, cassava, bean, and chickpea--alongside a fructooligosaccharide (FOS/inulin) control. Fecal inocula from three donors were used to simulate colonic fermentation. Total SCFA production showed that bean fiber (71mM) performed comparably to FOS (78mM) and outperformed potato and cassava. In terms of the target beneficial short-chain fatty acid, butyrate, beans and chickpeas yielded the highest proportions (16-17% of total SCFAs), exceeding FOS (14.7%) and outperforming potato and cassava (12-13%). For propionate, beans and chickpeas again led with 18-19%, followed by potato and cassava at 16%. The 20 isolated whole food fibers will be assessed for their in vitro fecal fermentation characteristics followed by assessment of whole food fiber mixtures in the summer and fall 2025, and the clinical trial is projected to begin in early 2026. Key Outcome: Pulse-derived fibers--particularly bean and chickpea--demonstrated superior prebiotic potential compared to tuber-derived fibers and inulin, promoting higher levels of butyrogenic and propiogenic bacterial activity.
Publications
|
Progress 05/01/23 to 04/30/24
Outputs
Target Audience:The project hypothesizes that whole food fibers are better for gut health than isolated added fibers. If shown to be true, our target audience will be a wide range of consumers who consume whole and processed foods where whole food fiber concentrates can be added. The food industry is a target audience for this research as they could incorporate whole food fiber concentrates and mixtures, determined from this project, in their food products. Another target audience are researchers and health professionals that will be informed of advancements in this area. In this period, we had a Purdue press release for the project athttps://ag.purdue.edu/news/2024/03/promoting-beneficial-gut-microbes-with-whole-food-dietary-fiber.html. Changes/Problems:The project started May 1, 2023, however we had difficulty in finding a graduate student with the appropriate background for the project (i.e., food and nutrition sciences, and clinical study experience). This delayed the start of laboratory work until January 2024. We are making good progress and expect that we can accomplish the project goals and objectives within the current project period. What opportunities for training and professional development has the project provided?We have trained two visiting scholars in fiber extraction procedures and in vitrofecal fermentations, short chain fatty acids analysis and bacterial DNA extraction. How have the results been disseminated to communities of interest?The project has been presented at theUSDA-NIFA 2024 Food and Human Health (A1343) Project Directors (PD) Meeting (Purdue University, 2024). What do you plan to do during the next reporting period to accomplish the goals?We plan to finalize in vitro fermentation experiments and related analyses, including short-chain fatty acids and qPCR analysis of Clostridium Cluster XIVa abundances, and based on these results, select the whole food dietary fiber mixture by the next reporting period. Additionally, we plan to have begun recruitment for the cross-over clinical trial using the selected mixture.
Impacts
What was accomplished under these goals?
We experienced a six-month start delay due to difficulties in hiring personnel. Currently, two visiting scholars are actively working on the project, and one will continue this fall as a graduate student. All whole food fibers have been sourced, freeze-dried and ground, and are now in the final stages of purification (starch and protein removal). We anticipate completing the in vitro fecal fermentation experiments for fiber mixture selection by the end of the fall.
Publications
|