Banca de DEFESA: IARA FERREIRA RESENDE

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE: IARA FERREIRA RESENDE
DATA: 15/04/2025
HORA: 14:00
LOCAL: online
TÍTULO:

MICROENCAPSULATION OF YEAST WITH PROBIOTIC ATTRIBUTES AND ITS APPLICATION IN THE TREATMENT OF
VANCOMYCIN-INDUCED DYSBIOSIS

PALAVRAS-CHAVES:

Probiotics, spray dryer, gut, dysbiosis, microbiome

PÁGINAS: 112
GRANDE ÁREA: Ciências Biológicas
ÁREA: Microbiologia
RESUMO:

easts are eukaryotic microorganisms found in natural environments, including plants, air, water, and food. Several studies have demonstrated that specific yeasts, when ingested, exert beneficial effects on host health and physiology, supporting their potential use as probiotics. This study aimed to develop a microencapsulation protocol for probiotic yeasts to enhance their viability and passage through the gastrointestinal (GI) tract and evaluate their efficacy in treating antibiotic-induced dysbiosis in BALB/c mice. The study was conducted in two phases. Phase I focused on selecting the encapsulating material and optimizing microencapsulation conditions for Saccharomyces cerevisiae (CCMA 0732) and Pichia kluyveri (CCMA 0615). Yeasts (10⁸ CFU/mL) were microencapsulated separately via spray drying using whey powder (WP; 15%, 20%, and 30%) and sodium alginate (ALG; 1%). Microcapsule characteristics and yeast viability were assessed over two months of storage at 4 °C and 25 °C. The selected formulations were applied in the fermentation of a probiotic functional beverage, and yeast survival and viability were evaluated under simulated GI tract conditions. The results indicated that yeast viability after spray drying was species-dependent and influenced by the encapsulating matrix. Notably, P. kluyveri microencapsulated with 15% WP + 1% ALG exhibited high viability under simulated GI conditions, both independently (>84%) and when incorporated into a food matrix (>94%). These findings highlight microencapsulation as a technological strategy to enhance yeast viability, improve biotechnological applications, and facilitate efficient probiotic delivery to the host. Phase II involved in vivo experiments using a vancomycin-induced dysbiosis model. Based on the results from Phase I, P. kluyveri microencapsulated with 15% WP was selected for application in the in vivo model. Thirty-two male BALB/c mice were divided into three experimental groups: Control (CG), Dysbiosis (DG), and Dysbiosis treated with yeast (YG). The DG and GY groups were subjected to dysbiosis induction via oral gavage with 100 µL of vancomycin (10 mg/mL) for 14 days, while the CG group received saline. Subsequently, the YG group received microencapsulated yeast (10⁸ CFU/mL) diluted in saline by gavage, whereas the other groups received only saline. Antibiotic treatment induced characteristic dysbiosis-related alterations, including an increased population of Enterobacteriaceae in feces, elevated white blood cell and total lymphocyte counts, increased spleen weight, and intestinal epithelial damage characterized by villous atrophy, inflammatory infiltration, and goblet cell hyperplasia. Yeast administration following antibiotic exposure significantly mitigated these effects, restoring most parameters to control-like levels. Microbiome analysis revealed that vancomycin reduced the relative abundance of Bacillota while promoting Verrucomicrobiota and Patescibacteria, along with an increase in potentially pathogenic genera such as Agathobaculum and Lachnoclostridium. Notably, P. kluyveri CCMA 0615 administration specifically enriched the Verrucomicrobiota phylum, particularly the beneficial genus Akkermansia. In conclusion, these findings suggest that microencapsulated P. kluyveri CCMA 0615 holds promise as a probiotic candidate for mitigating antibiotic-induced intestinal disorders and promoting gut health.

MEMBROS DA BANCA:
Externo à Instituição - CÍNTIA LACERDA RAMOS - UFVJM (Membro)
Interno - DISNEY RIBEIRO DIAS (Membro)
Externo à Instituição - ELIZABETHE ADRIANA ESTEVES - UFVJM (Membro)
Externo à Instituição - FRANCESCA SILVA DIAS NOBRE - UNIVASF (Membro)
Externo à Instituição - LAUANE GOMES - UFVJM (Suplente)
Interno - ROBERTA HILSDORF PICCOLI (Suplente)
Presidente - ROSANE FREITAS SCHWAN (Membro)
Interno - NÁDIA NARA BATISTA - UFLA (Membro)