On July 9th, Coco (Kehan) Zhang successfully defended her MSc. thesis titled, The fecal microbiome and metabolome signature in adult lean and obese cats fed an isoenergetically reduced macronutrient diets.
Read on for more information about Coco and her thesis!
Can you provide a summary of your thesis?
This thesis explored the fecal microbiota and metabolome signatures in lean and obese cats in response to a low carbohydrate, a low protein, or a low fat diet when fed at maintenance. Compared to lean cats, obese cats had an increased abundance of bacteria belong to Firmicutes phyla, and predicted enriched pathways were potentially associated with energy accumulation and fatty acid metabolism. Results from metabolomics study found higher concentrations of fecal proteinogenic and branched-chain amino acids, as well as pyruvic acid and sugars in lean cats. Regardless of body conditions, microbiota alterations were also observed across different diet groups, particularly within the Firmicutes, Bacteroidetes, and Actinobacteria phyla. These changes are attributed to the varying availability of substrates for bacterial fermentation. The metabolome study corroborates these findings, showing the greatest concentrations of fecal D-galactose and tryptophan were noted in the LP and LF diet, respectively. These findings highlight that both body condition and diet can significantly influence the fecal microbiota and metabolome in cats.
What’s next for you?
I’m planning to start a career in the pet food industry, aiming to become a formulator or product developer! But before I jump into that, I’ll head back to China to catch up with family and friends! It’ll be nice to take a break and spend some quality time with loved ones before starting the new chapter.
![](https://ovcpetnutrition.uoguelph.ca/files/2024/07/Screenshot-2024-07-04-at-11.10.28-AM.png)
Research challenges you had to overcome?
During my research, I faced a significant challenge related to the process of DNA extractions. After I extracted DNA from all samples using a commercial kit by following the provided protocol, the subsequent PCR did not yield the expected results. I thought the issue could be due to an inappropriate quantity of DNA, either too little or too much by using the standard volume. Therefore, I tried with varying amounts of DNA, using half or double the standard volume. Unfortunately, these adjustments did not fix the issue. Collaborating with a lab technician, we re-extracted DNA from some samples, but we were unable to detect any DNA. Despite trying all possible steps and involving different individuals in the extraction process, we were unable to identify the cause of the problem. This led us to consider the possibility that the issue might lie with the commercial extraction kit itself. We decided to test by using a different commercial extraction kit from another manufacturer.
To our relief, this approach was successful! Consequently, we ordered another kit and restarted the extraction process for all samples. This troubleshooting process was time-consuming, taking almost two months to resolve. However, it was a valuable learning experience. It underscored the importance of problem-solving skills and the necessity of considering all possible factors when faced with a challenge in scientific research. It also highlighted the importance of collaboration and the value of different perspectives in overcoming obstacles.
Future goals in pet nutrition?
My future goals in pet nutrition are deeply influenced by the belief that our pets should receive the same level of nutritional care as humans. I had a chance to intern at Champion Petfoods for two weeks during my master’s second year, which was an enlightening experience. It gave me a firsthand look at the pet food industry and inspired me to aspire to be a pet food formulator. Additionally, my research showed me how crucial diet is and how obesity can affect their microbiome and health. So, I hope to develop diets to improve pets’ health, longevity, and quality of life.
![](https://ovcpetnutrition.uoguelph.ca/files/2024/07/MicrosoftTeams-image-1-768x1024.jpg)
Photo of (from left to right) Dr Adronie Verbrugghe, DVM, PhD. and Coco (Kehan) Zhang BScH, MSc.
Funding Statement: Coco’s research project was supported by NSERC, Mitacs and Champion Petfoods. We thank you for your contributions.