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Marwa Zaied: New Insights from TMAO and Colorectal Cancer Research

Marwa Zaied/LinkedIn

Aug 31, 2025, 20:00

Marwa Zaied: New Insights from TMAO and Colorectal Cancer Research

Marwa Zaied, Head of the Department of Medical Oncology at the Birket Elsaba General Hospital, shared a post on LinkedIn:

“TMAO and Colorectal Cancer: New Insights from Research

What is TMAO?

Trimethylamine N-oxide (TMAO) is a gut microbiota–derived metabolite formed from dietary choline and carnitine (red meat, eggs, high-fat dairy), especially in large intakes.

Key Evidence:

A large prospective study (PLCO Cancer Screening Trial, Cancer 2024) showed that higher serum TMAO nearly doubled the risk of distal colorectal cancer (OR ≈ 1.90; 95% CI: 1.24–2.92).

Elevated choline also increased risk (OR ≈ 1.26), though it was inversely related to rectal cancer.

Red meat intake correlated with higher TMAO levels.

Mechanistic studies reveal that TMAO can stimulate tumor growth and angiogenesis by upregulating VEGFA.

Nutritional Strategies to Reduce TMAO:

Limit red and processed meat.
Adopt a plant-forward diet (whole grains, legumes, fruits, vegetables).
Support gut health with probiotics and fermented foods.
Increase dietary fiber → reduces microbial TMA formation.
Include omega-3 sources (fatty fish, walnuts, flaxseed).
Consider mixed tree nuts → shown in trials to lower plasma TMAO.

Clinical takeaway:

Personalized nutrition focusing on gut microbiome modulation and TMAO reduction could be a preventive strategy against colorectal cancer.”

Title: Associations of serum trimethylamine N-oxide and its precursors with colorectal cancer risk in the Prostate, Lung, Colorectal, Ovarian Cancer Screening Trial Cohort

Journal: American Cancer Society Journal

Authors: Doratha A. Byrd, Semi Zouiouich, Smriti Karwa, Xinmin S. Li, Zeneng Wang, Joshua N. Sampson, Erikka Loftfield, Wen-Yi Huang, Stanley L. Hazen, Rashmi Sinha

Read the full article.

Marwa Zaied