A Lactobacillus delbrueckii subsp. bulgaricus fermented skimmed milk powder has limited effects on gastrointestinal health in healthy individuals with mild-to-moderate gastrointestinal symptoms: resul

Hormones are important for the optimum functioning of the human body, thyroid hormones in particular are essential for development and growth of vital organs, reproduction and the regulation of metabolism, with extreme levels of the thyroid hormones causing clinical complications. Some common thyroid disorders include hypothyroidism and hyperthyroidism, which are mainly affected by determinants such as intake of iodine, genetic predisposition, chemicals, age, smoking and some therapeutic agents such as immune checkpoint inhibitors. Although thyroid cancer is seen to have low mortality, it is one of the fastest growing diseases affecting people worldwide (). The GLOBOCAN database which records thyroid cancer cases amongst 185 countries in 2020, presented an age-standardized incidence of 10.1 per 100,000 women and 3.1 per 100,000 men. Fortunately, the age-standardized mortality rate was comparably lower with 0.5 per 100,000 women and 0.3 per 100,000 men for thyroid cancer. The incidence rates among women had high variation across different regions, whereas the mortality had remained the same, this signifies the important impact of environmental determinants on the identified burden of thyroid disease (). Iodine is known as the most important factor contributing to good thyroid health as it is a part of the synthesis of the thyroid hormone, with extreme levels of iodine causing abnormalities in thyroid function. Deficiencies in iodine is a public health issue combated by universal salt iodization (USI) programs, which has led to improved population health outcomes over the past few decades (, ). With time, populations are moving towards iodine sufficiency, creating shifts in thyroid disease patterns and differences in the prevalence of thyroid cancer subtypes to less aggressive forms. Therefore, ensuring the uptake of optimum levels of iodine has become a standard in public health measures across countries. Other than iodine, thyroid disrupting chemicals (TDCs) have been a cause for concern in the environment. Chemicals such as bisphenol A (BPA) and polychlorinated biphenyls (PCBs) can affect thyroid function and promote autoimmune thyroiditis. These compounds have been the major cause for hypothyroidism in environments with sufficient iodine. High levels of these compounds collect into marine animals, which makes seafood consumption result in both high iodine intake and high exposure to TDCs. This double effect is one of the reasons why it is significant to compare thyroid diseases amongst coastal and inland communities and understand any underlying differentiating factors (). An ecological study performed in Canada identified a skewed distribution of hypothyroidism in the coastal communities of Newfoundland, which may be due to the thyroid disease risk being affected by the proximity to coasts (). Although such studies suggest a relationship between geography and incidence of thyroid diseases, the evidence is scattered, heterogeneous and locally based without systematic compilation.