PhD defence and trial lecture: Saima Rehman

Thesis title​​​:

Diet-induced inflammation in zebrafish and its alleviation by functional oligo- and polysaccharides

Trial lecture topic:

Interplay between feed, microbiota and gut-brain axis

Evaluation Committee​:

• Senior Researcher Aleksei Krasnov, Nofima, Ås
• Assistant Professor Mahsa Jalili, University of Copenhagen, Denmark
• Associate Professor Hetron Mweemba Munang'andu, Nord University

Supervisory Committee:

• Main supervisor: Professor Kiron Viswanath, Nord University
• Co-supervisor: Associate Professor Sylvia Brugman, Wageningen University & Research, Netherlands
• Co-supervisor: Professor Jorge Fernandes, Nord University
  

About the thesis​:

It is widely recognized that intestinal inflammation is a major health problem in humans. Certain dietary components can evoke an inflammatory status in the intestine due to their ability to disrupt the intestinal barrier. On the other hand, some natural bioactive compounds can prevent the development of intestinal inflammation.

This PhD project elucidated the molecular characteristics and extraintestinal effects of soybean meal-induced intestinal inflammation in zebrafish. The ability of dietary β-glucans (yeast and alga-derived) and alginate oligosaccharides to counter soybean meal-induced inflammation in zebrafish was also studied to reveal the efficacy of the bioactive compounds. Transcriptome and metabolome-based studies were employed to delineate the markers of inflammation. Furthermore, soybean meal-induced inflammation was associated with defects in development and locomotor activity of zebrafish. The interesting finding is that algal β-glucans and alginate oligosaccharides restored the expression of inflammation marker genes altered by soybean meal diet. The algal β-glucan prevented the developmental defects and normalized the soybean meal diet-induced changes in the locomotor behavior of zebrafish. The alginate oligosaccharides and algal beta-glucans could elevate the abundance of a short chain fatty acid and vitamin in the plasma of zebrafish, respectively.

The PhD project gave insights into diet-induced inflammatory features and distinct modes of action of β-glucan and alginate oligosaccharides to counteract inflammation and associated extraintestinal manifestations.