An In Vitro Study of the Influence of Curcuma longa Extracts on the Microbiota Modulation Process, In Patients with Hypertension

Abstract

The multiple causes of cardiovascular diseases signify a major incidence and developmental risk of this pathology. One of the processes accountable for this pathologic development is the instauration of dysbiosis and its connection with an inflammatory process. Low antioxidant colonic protection encourages the progression of inflammation, with cardiovascular dysfunctions being a secondary consequence of the dysbiosis. Curcumin is one of the bioactive compounds displaying promising results for the reduction of an inflammatory process. The present study aims at demonstrating the capacity of three extracts drawn from Curcuma (C.) longa through an in vitro simulation process, for microbiota modulation in patients with hypertension. The acidic pH in the extraction process determined a high curcumin content in the extracts. The major phenolic compound identified was curcumin III, 622 ± 6.88 µg/mL for the ethanol/water/acetic acid extract. Low EC50 values were associated (0.2 µg/mL for DPPH scavenging activity) with the presence of curcumin isomers. A metabolic pattern became evident because the relationship between the short-chain fatty acids acted as a clinical biomarker. The curcumin present stimulated the formation of butyric and propionic acids. Microbiota activity control included a high degree of curcumin degradation and biotransformation in the other phenolic compounds. This developmental process was supported by the progression in the enterobacteria with a corresponding escalation in the pH level. The metabolomic pattern demonstrated a performance similar to the administration of dietary fibre, with the positive effects being dose-dependent.

Correlations between Microbiota Bioactivity and Bioavailability of Functional Compounds: A Mini-Review

“…The claim is justified by increasing the amount of CO 2 formed, which can support the use of the carbon source (data unpublished as of yet), by probiotic yeasts (S. cerevisiae and S. boulardii). This aspect has been demonstrated by previous studies that have shown the selective use, by certain strains, of bioactive components in extracts [29,52]. Increasing the number of favorable strains in the microbial pattern of the microbiota can thus have two causes, as detailed below:…”

“…They differently modulate the microbiota, favoring the development of some bacterial strains, and act like a prebiotic. A recent study revealed that the Curcuma longa extract with a high curcumin content (Table 1) modulates the microbiota of patients with hypertension by improving the ratio of SCFAs, which strongly influences the Enterobacteriaceae group and negatively influences the Bacteroides-Prevotella-Porphyromonas groups [29]. Polyphenols from the Lonicera caerulea L. berry reduced the Firmicutes/Bacteroidetes ratio in the fecal microbiota of a mouse model with an induced high-fat diet (HFD) and increased the relative abundance of Bacteroides and Parabacteroides.…”

“…Normally, they are used as a carbon source by probiotic strains of the genus Lactobacillus and Bifidobacterium, but their role is much more complex. Their catabolism regulates the synthesis of SCFAs and corrects the microbial pattern in degenerative pathologies [2,29]. Partial in vitro studies conducted at the Faculty of Biotechnologies, Bucharest, Romania showed that the polyphenols present in matcha tea and green tea adopt a selective metabolization, the assimilation rate of which is about 20% (data unpublished as of yet).…”

“…• Reduction (inhibition) of some pathogen strains and the release of ecological niches where Lactobacillus strains, for example, can proliferate [29].…”

“…The antimicrobial effects of polyphenols are exerted by several mechanisms, such as: direct action on certain target bacterial strains, reducing the adhesion capacity of pathogenic strains, or disrupting ionic fluxes at the cell membrane [22,28]. One of the main mechanisms by which these compounds act is by stimulating the multiplication of favorable strains [29] for correcting the microbial and metabolomic patterns [1]. The bioavailability of the functional components represents the property that controls the bioactivity in vivo.…”