Black Raspberry Consumption Significantly Promotes Gut Microbiome Health in Cancerous Mice but Not in Healthy Mice

Fan He
Graduate (PhD)
Jiyoung Lee
Food Science and Technology

Black raspberries (BRBs) are a super food due to high level of bioactive phytochemical compounds and has gained great popularity as a health and wellness dietary component. Previous research reported that intake of BRB or derived bioactive phytochemical extracts, particularly polyphenol-rich fractions, could reduce chronic inflammation and prevent cancer progression. While previous studies reported health benefits of BRB consumption, there is limited knowledge about the benefits of dietary BRB on the gut microbiome in cancer-prone populations. This study was focused on examining the impact of BRBs on gut microbial structure and bacterial abundance in a hepatocellular carcinoma mouse model. Mice were assigned into 4 groups: Normal; Normal+BRB; Cancer; Cancer+BRB. Cancer groups were single-injected with 5 µg/mg diethyl-nitrosamine (DEN, cancer initiator) at 4 weeks age. BRB groups were fed control diet supplemented with freeze-dried BRB powder for 36 weeks. Aggregate fecal samples by cage were collected every 8 weeks. The Cancer+BRB group showed significantly higher bacterial diversity and richness than the Cancer group (p<0.01), while no significant differences found between Normal groups. BRB diet diminished the enrichment of Proteobacteria in the Cancer+BRB group compared to the Cancer group. Lachnospiraceae and Clostridiales vadin BB60, which are associated with short chain fatty acid production, were significantly higher in the Cancer+BRB group. In the Normal+BRB group Erysipelotrichaceae, which is correlated with inflammation-related disorder, was significantly less abundant than in the Normal group. The Cancer+BRB group showed an extremely high interconversion between arginine, ornithine, and proline compared to the Cancer group, which is associated with the inhibition of gastrointestinal diseases. Our results illustrate BRB diet drives beneficial alterations on the gut microbial community in the cancer risk group, whereas no significant effects of BRBs were observed in the non-cancer group. We conclude that BRB intake can positively regulate the bacteria composition, limit the progression of cancer and inflammation, improve the metabolism of beneficial compounds and induce recovery effects most evident in the cancer group. Leveraging future metagenomic sequencing and bioinformatic strategies will further extract impactful information on metabolomics, functions, gene and pathway functionality, and higher resolution taxonomic profiling to advance our understand BRB-dependent mechanisms.