Tomato seed extract promotes health of the gut microbiota and demonstrates a potential new way to valorize tomato waste

Authors: Firrman, Jenni; Narrowe, Adrienne; Liu, Linshu; Mahalak, Karley; Scarino Lemons, Johanna; VAN DEN ABBEELE, PIETER - Cryptobiotix; BAUDOT, AURELIEN - Cryptobiotix; DEYAERT, STEF - Cryptobiotix; LI, YANFANG - University Of Maryland; YAO, YUANHANG - University Of Maryland; YU, LIANGLI - University Of Maryland

Submitted to: PLOS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/14/2024
Publication Date: 4/16/2024
Citation: Firrman, J., Narrowe, A.B., Liu, L.S., Mahalak, K.K., Scarino Lemons, J.M., Van Den Abbeele, P., Baudot, A., Deyaert, S., Li, Y., Yao, Y., Yu, L. 2024. Tomato seed extract promotes health of the gut microbiota and demonstrates a potential new way to valorize tomato waste. PLOS ONE. 19(4):e0301381. https://doi.org/10.1371/journal.pone.0301381.
DOI: https://doi.org/10.1371/journal.pone.0301381

Interpretive Summary: Tomatoes are one of the most popular vegetables around the world. One remarkable benefit of this agricultural commodity is the ability to process it into products that are both flavorful and stable at ambient temperature for long periods of time, i.e., tomato sauce, tomato puree, salsa, and ketchup. The increased popularity of tomato products coupled with the need for nutritious components to feed a growing population calls for novel strategies to utilize and/or repurpose tomato waste generated from processing. Here, compounds extracted from tomato seeds (tomato seed extract) isolated from tomato waste (pomace) were tested for their ability to affect the gut microbiota, a dense community of microbes within the colon that play an important role in human health and progression of disease. The results found that the tomato seed extract was able to selectively enhance levels of beneficial microbes, known as Bifidobacteria, and increase levels of healthy byproducts produced by the gut microbiota. These effects were observed in all donors tested and are associated with a positive health outcome. In summary, these results show that tomato seed extract obtained from tomato waste can be used to shape the gut microbiota in a healthy manner and provides a potential new strategy to gain value from tomato waste and increase sustainability by creating new functional foods.

Technical Abstract: The current efforts to valorize food byproducts to increase sustainability and reduce food losses have stimulated interest in utilization of waste components as health-promoting supplements. Tomato seeds are often discarded in tomato pomace, a byproduct of tomato processing, yet these seeds are known to contain an array of compounds with biological activity and prebiotic potential. Here, extract from tomato seeds (TSE), acquired from pomace, was evaluated for its ability to effect changes on the gut microbiota using an ex vivo strategy. The results found that TSE significantly increased levels of the beneficial taxa Bifidobacteriaceae in a donor-independent manner, from a range of 18.6-24.0% to 27.0-51.6% relative abundance following treatment, yet the specific strain of Bifidobacteriaceae enhanced was inter-individually variable. These structural changes corresponded with a significant increase in total short-chain fatty acids, specifically acetate and propionate, from an average of 13.3 to 22.8 mmol/L and 4.6 to 7.4 mmol/L, respectively. Together, these results demonstrated that TSE has prebiotic function by shaping the gut microbiota in a donor-independent manner that is beneficial to human health. These findings provide a novel application for TSE harvested from tomato pomace and demonstrate the potential to further valorize tomato waste products.