Bacteria are a type of microorganism with different shapes and structures. In bacteriology, they are mainly classified into two main types, gram-negative and gram-positive, based on the physical and chemical properties of the cell wall.

The migration of potentially harmful bacteria or their toxic products from one site of the body (such as the gut) to other organs or tissues due to compromised barrier integrity.

BALB/c mice are a widely used strain of laboratory mice commonly used in biomedical research (i.e., including immunology, oncology, and infectious disease research) due to their genetic uniformity, susceptibility to certain diseases, and ability to produce high levels of antibodies (Brodkin, 2007; Willott et al., 1998).

The basal ganglia is a part of the brain comprising multiple structures that primarily modulate motor tone and involuntary motor movement. Damage to this area is implicated in movement disorders such as Parkinson’s Disease.

Behavioral mechanisms refer to the processes and actions that govern an individual’s behavior. These mechanisms encompass how people respond to stimuli in their environment, make decisions, and engage in various activities.

A relationship that goes both ways, with each variable of interest affecting the other.

Binge eating is defined as episodes of rapid, out-of-control eating accompanied by a sense of powerlessness over the quantity and quality of food consumed (Gaete et al., 2021).

Biological classification groups living organisms based on their shared characteristics, reproduction, mobility, appearance, and functionality. Simply put, it is like a system of filling cards in the library. Each card represents a species and is filled in the order in a folder with other species with the same similarities or characteristics (Khawaldeh et al., 2017).

The blood-brain barrier is a protective layer of cells and blood vessels surrounding the brain and spinal cord. It acts like a filter that prevents harmful substances, such as toxins and germs, from entering the brain and damaging its delicate tissues. The BBB allows only certain substances, like oxygen, glucose, and some medications, to pass through and enter the brain. This helps to maintain a stable and healthy environment for the brain to function correctly.

Brain-derived neurotrophic factor (BDNF) is a protein involved in the growth, maturation, and survival of nerve cells in the brain. It plays a vital role in learning and memory and is critical for cell-to-cell neuronal communication within synapses (Castrén & Monteggia, 2021). In the context of the diet-mental health relationship (DMHR), a healthy and nutritious diet elevates the level of BDNF, resulting in improved metabolic and cognitive health.