Search

Introduction: The Brazilian Amazon has one of the richest biomes and the largest source of freshwater on the planet. However, anthropogenic activities have also turned this region into one of the highest points of human exposure to mercury ever recorded. Therefore, the aim of the present work was to perform a scope review with meta-analysis in order to evaluate the total mercury (THg) and methylmercury (MeHg) levels in Brazilian Amazon fish, as well as to carry out a local population health risk assessment. Methods: A literature search was systematically performed in research databases and gray literature, remaining 14 studies from 2017 to 2022 for final analysis. The studies were submitted to raw mean and subgroup meta-analysis, followed by a risk characterization and the calculation of a maximum safe consumption of fish for the Amazonian population. Results: The selected studies covered 4 Amazonian states, as well as included the analysis of >30 fish species of different trophic levels and sampling in >15 cities. The overall total mercury mean obtained for Brazilian Amazon fish was 0.29 ug g⁻¹. Significant difference was observed between THg levels according to fish trophic level (p < 0.05), which reinforces the MeHg biomagnification. When THg levels from all fish samples were pooled, it was not observed a significant difference among the Amazonian states and the fish sampling season. However, significant variations between microregions and species-specific variations over the seasons should not be discarded. All estimated daily methylmercury intake exceeded the reference dose of 0.1 ug kg BW⁻¹ day⁻¹, resulting in a hazard quotient (HQ) greater than 1 and indicating a risk of chronic exposure by the local population. The maximum safe consumption of fish calculated based on the overall total mercury mean was set as 31, 147 and 173 g week⁻¹ for children, adult women and adult men, respectively, which is much lower than the reality of consumption by the riverside communities (2870 g week⁻¹). Conclusion: There is an urgent need to reduce Hg exposure levels in the region as well as to recommend other protective nutritional strategies to the local population such as defining the fish species with lower mercury contamination levels and their safe weekly consumption.

Flaxseed (Linum usitatissimum L.) displays functional properties and contains α-linolenic acid (omega-3). It also contains soluble and insoluble fiber, lignans, phenolic acids, flavonoids, phytic acid, vitamins, and minerals. However, its microbiota can cause fungal contaminations, drastically reducing its quality. The objective of this work was to identify the fungi present in bulk flaxseed through the internal transcribed spacer (ITS1) intergenic region using a metataxonomics approach. Fungal identification was performed via high-performance sequencing of the ITS1 region using ITS1 (GAACCWGCGGARGGATCA) and ITS2 (GCTGCGTTCTTCATCGATGC) as primers with 300 cycles and single-end sequencing in the MiSeq Sequencing System equipment (Illumina Inc., San Diego, CA, USA). Six genera and eight species of fungi were found in the sample. The genus Aspergillus stood out with three xerophilic species found, A. cibarius, A. Appendiculatus, and A. amstelodami, the first being the most abundant. The second most abundant genus was Wallemia, with the species W. muriae. This is one of the fungi taxa with great xerophilic potential, and some strains can produce toxins. Metataxonomics has proved to be a complete, fast, and efficient method to identify different fungi. Furthermore, high-performance genetic sequencing is an important ally in research, helping to develop novel technological advances related to food safety.

Irritable bowel syndrome (IBS) is a chronic condition that affects 11.2% of the world’s population. The management of gut microbiota using probiotic and synbiotic agents might be a valid alternative to assist in the treatment of IBS. The focus of this study was to evaluate the effects of prebiotic and synbiotic compounds carried by different foods on major symptoms of IBS through a systematic literature review. MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and LILACS were accessed during July 2021. The studies included in this review were the ones that tested volunteers older than 16 years of age and were conducted using a randomized, controlled clinical trial. The risk of bias was assessed by using the Cochrane risk-of-bias tool for randomized trials (RoB2). Furthermore, the data found were qualitatively evaluated due to the studies’ differences. Two papers were able to fit the criteria, with a total sample size of 280 participants. No datum was found regarding the use of prebiotics in the treatment of IBS. Synbiotic agents, however, had a positive effect on gastrointestinal symptoms and the participants’ overall bowel satisfaction; however, it was not possible to reach a consensus on which effects. Further studies regarding the use of synbiotics and prebiotics must be carried out to determine which effects are the most significant in the treatment of IBS.