Crit Rev Food Sci Nutr. 2015 Apr 7:0. [Epub ahead of print]

Bioactivation of Phytoestrogens: Intestinal Bacteria and Health.

Landete JM1, Arqués J, Medina M, Gaya P, De La Rivas B, Muñoz R.

• 1a Departamento de Tecnología de Alimentos , Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA) . Carretera de La Coruña Km 7.5, 28040 Madrid ( Spain ).

Abstract

Phytoestrogens are polyphenols similar to human estrogens found in plants or derived from plant precursors.

Phytoestrogens are found in high concentration in soya, flaxseed and other seeds, fruits, vegetables, cereals, tea, chocolate, etc.

They comprise several classes of chemical compounds (stilbenes, coumestans, isoflavones, ellagitannins and lignans) which are structurally similar to endogenous estrogens but which can have both estrogenic and antiestrogenic effects.

Although epidemiological and experimental evidence indicates that intake of phytoestrogens in foods may be protective against certain chronic diseases, discrepancies have been observed between in vivo and in vitro experiments. The microbial transformations have not been reported so far in stilbenes and coumestans.

However, isoflavones, ellagitanins and lignans are metabolised by intestinal bacteria to produce equol, urolithins and enterolignans, respectively.

Equol, urolithin and enterolignans are more bioavailable, and they have more estrogenic/antiestrogenic and antioxidant activity than their precursors.

Moreover, equol, urolithins and enterolignans have antiinflammatory effects and induce antiproliferative and apoptosis-inducing activities.

The transformation of isoflavones, ellagitanins and lignans by intestinal microbiota is essential to be protective against certain chronic diseases, as cancer, cardiovascular disease, osteoporosis and menopausal symptoms.

Bioavailability, bioactivity and health effects of dietary phytoestrogens are strongly determined by the intestinal bacteria of each individual.

KEYWORDS:  Phytoestrogens; enterodiol; enterolactone; equol; microbiota; urolithin

PMID:  25848676