Cognitive reserve is the brain’s capacity to resist the effects of aging or neurological damage by efficiently reorganizing its neural networks or using alternative neural networks to achieve desired cognitive goals.

Cognitive resilience is the brain’s ability to adapt and recover from cognitive challenges, stress, or aging while maintaining normal cognitive function. It reflects the capacity to withstand cognitive decline or recover cognitive abilities after setbacks.

In microbiology, a Colony-Forming Unit (CFU) determines the concentration of bacteria, fungi, and other microbes in a sample.

Comfort foods are familiar and emotionally satisfying dishes that provide a sense of psychological comfort in times of stress or distress. They are not necessarily chosen for their nutritional value but for the positive emotions they evoke, offering a sense of reassurance and relief during challenging or emotionally charged moments.

A group of beneficial organisms that live in harmony within the human gut and carry out various functions, from digesting complex dietary fibers and producing essential vitamins (K, B) to inducing protective immune responses against pathogenic microbes (Fung et al., 2014).

A commensal relationship is an organism-to-organism relationship in which one species benefits from the presence of another species in terms of food or other benefits without harming or benefiting the other (J Hellmann, 2013). Commensal bacteria are an example of a commensal relationship between the host (i.e., human) and bacteria.

Comparative abundance is a metric that allows us to investigate different microbial populations by comparing the relative quantities of two or more species. While isolating and quantifying each bacterial strain is difficult, changes in relative abundance can help track the microbiome’s composition and point to potential effects within the MGBA.

Compensatory behaviors refer to the drastic measures (e.g., excessive exercise, self-induced vomiting, or restricting food intake) taken by people with eating disorders in an attempt to “compensate” for eating and consuming calories, as well as the negative emotions elicited by this, such as shame, anxiety, and guilt (Colleen Stiles-Shields et al., 2012; Neale & Hudson, 2020).

Compulsive eating, also known as binge eating or emotional eating, refers to a pattern of consuming large quantities of food in a short period, often accompanied by a feeling of loss of control during the eating episode.

Conative processes refer to mental activities underpinning conscious, goal-directed behavior. They include intention, desire, will, and striving and represent the motivational aspect of the mind. Conative processes are one of the three components of the previously mentioned three-part categorization of psychological processes (along with affective and cognitive processes).