How does olive oil affect gut health?

By Tarun Sai LomteReviewed by Susha Cheriyedath, M.Sc.Jul 9 2025

Researchers reviewed how olive-derived bioactive compounds, including polyphenols, secoiridoids, and triterpenes, modulate the gut microbiota and promote intestinal health.

Review: Exploring the Impact of Olive-Derived Bioactive Components on Gut Microbiota: Implications for Digestive Health. Image Credit: sebra / Shutterstock

In a recent study published in the journal Foods, researchers in Spain reviewed the effects of bioactive compounds derived from olives on the composition and function of the gut microbiota.

Food is increasingly recognized for its capacity to modulate microbial ecosystems. Dietary components act as substrates for microbial growth and exert selective pressures to influence microbial community composition, gene expression, and synthesis of bioactive metabolites (phenolic derivatives, short-chain fatty acids [SCFAs], and secondary bile acids). Functional foods are those with components capable of reducing disease risk and promoting health.

These components include insoluble and soluble fibers that function as prebiotics, which are fermented to produce SCFAs, as well as other bioactive compounds that interact with the host and microbiota. Studying these components and their mechanisms will help design effective strategies to prevent digestive disorders and enhance overall well-being. The Mediterranean diet (MD) is a dietary pattern rich in functional elements that places olive and its derivatives, particularly extra-virgin olive oil (EVOO), at the base of the nutrition pyramid.

Olive byproducts are valuable across various industries, including cosmetic, nutraceutical, bioenergy, and pharmaceutical sectors. Nonetheless, there is no comprehensive analysis on olive-derived products and their impact on the gut microbiota. Therefore, the present study synthesized evidence on the effects of olive bioactive compounds on the gut microbiota, focusing on mechanisms of action, therapeutic potential, and opportunities.

Olive and its bioactive compounds

The olive tree is native to the Mediterranean region and is cultivated for its oil and fruit. Various parts of the olive tree are recognized for their functional ingredients, nutritional value, and bioactive compounds. The olive fruit contains phenolic compounds, dietary fiber, and triterpenes. Olive oil is a substantial source of monounsaturated fatty acids (MUFAs), especially oleic acid. It also contains phytosterols, tocopherols, polyphenols, and squalene, all of which are linked to various health benefits.

Olive leaves are a byproduct of olive cultivation and pruning. They are rich in secoiridoids and flavonoids, which exhibit anti-inflammatory and antioxidant properties. Olive mill wastewater is a reservoir of water-soluble phenolics; its antimicrobial, anti-inflammatory, and antioxidant potential has attracted considerable interest, making it a valuable resource for recovering functional ingredients.

Olives contain numerous bioactive compounds with potential health benefits. Phenolic compounds, such as flavonoids, phenolic acids, and polyphenols, are the most studied bioactive compounds due to their diverse biological activities. Olive contains more than 170 polyphenols, known for their antioxidant properties. They also exert prebiotic-like effects, shaping the gut microbiota and augmenting the bioactivity of phenolics.

Oleuropein is a secoiridoid with neuroprotective, anticancer, anti-inflammatory, and antimicrobial actions. It is reported to modulate beneficial gut and skin microbiota. Tyrosol is a prominent phenolic compound in wine and olive oil, recognized for its neuroprotective and cardioprotective properties. Other key compounds include oleocanthal, known for its notable anti-inflammatory properties similar to ibuprofen, and oleacein, another secoiridoid with potent antioxidant effects. The paper also discusses terpenoids such as maslinic and oleanolic acid, which show promise in modulating gut health.

Main bioactive compounds in olives.

Effects of olive oil and its components on gut microbiota

Olive oil not only contributes to health through its high MUFA content but also by providing diverse bioactive compounds. These compounds interact with the gut microbiota in a bidirectional manner. For instance, microbes convert olive oil constituents into new metabolites, while the same compounds reshape the microbial community, promote beneficial taxa, boost SCFA production, and restrain harmful microbes.

The lipid-rich matrix of olive oil facilitates the intestinal uptake of phenolic compounds and fosters microbial communities associated with a lower inflammatory tone. In turn, the gut microbiota metabolizes olive polyphenols. Consistent evidence suggests that bioactive compounds in olives can modulate the gut microbiota, leading to beneficial effects on gut health in both humans and animals. These compounds promote a balanced microbial ecosystem, augment intestinal barrier integrity, and reduce inflammation.

Olive bioactive compounds have shown promising therapeutic potential in various gastrointestinal (GI) disorders, including colitis, intestinal inflammation, and obesity. Hydroxytyrosol is a derivative of oleuropein biotransformation in the GI tract, and it is the most commonly used compound in human and animal studies. It can activate the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway, helping counteract oxidative stress by producing antioxidant enzymes.

Moreover, hydroxytyrosol may modulate key transporters and enzymes involved in the synthesis, conversion, and excretion of bile acids, improving bile acid metabolism and gut health. It can also decrease pro-inflammatory cytokine levels, alleviate intestinal inflammation, and modulate the synthesis and function of tight junction proteins in the intestinal epithelium, thereby strengthening the intestinal barrier.

Tyrosol is another olive-derived polyphenol that has been studied in relation to gut microbiota interactions. It has demonstrated promising therapeutic potential for several GI disorders due to its interactions with the intestinal barrier. It can mitigate colitis symptoms, reduce mucosal damage by enhancing intestinal barrier integrity, and promote the expression of tight junction proteins. Tyrosol can also improve the proliferation of beneficial bacteria, especially Bifidobacteriaceae and Lactobacillaceae.

The researchers note that some of these benefits may arise from the synergistic action of these compounds working together, rather than from any single component in isolation.

Challenges and the Path Forward

However, the researchers caution that significant challenges remain before these findings can be translated into clinical advice. The paper highlights that much of the current evidence comes from animal studies, and results may not be directly applicable to humans due to differences in genetics, diet, and gut physiology. The authors also highlight the challenges in standardizing olive oil composition for studies and the inherent natural variability of the human gut microbiota, which makes it challenging to draw universal conclusions. Therefore, they call for more well-designed, long-term human clinical trials to confirm these promising results and gain a better understanding of individual responses.

Concluding remarks

Taken together, olive oil-derived secoiridoids, polyphenols, and triterpenes engage in bidirectional communication with the gut microbiota to shape the production and balance of microbial metabolites, including SCFAs, neurotransmitters, phenolic derivatives, and secondary bile acids. Translating these insights into functional products and dietary recommendations will require multidisciplinary studies integrating clinical trials with systems biology and multi-omics approaches. By deepening our mechanistic understanding and addressing these research gaps, we could fully unlock the therapeutic potential of olive bioactives for metabolic, inflammatory, and gut-brain axis-related disorders.

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