This study is evaluating the levels of calprotectin, a protein found in stool, in healthy adults. Calprotectin is a marker of inflammation in the intestines and can help doctors tell the difference between inflammatory bowel diseases (IBD), like Crohn's disease or ulcerative colitis, and non-inflammatory conditions like irritable bowel syndrome (IBS).

In this study, healthy volunteers aged 22 and older will collect a stool sample at home using a simple kit and mail it to the study site. The samples will be tested using a new laboratory method called the ALPCO Calprotectin CLIA assay. The goal is to confirm what level of calprotectin is considered "normal" in people without intestinal disease.

Participation involves just one stool sample, and there are no medical procedures. Volunteers will be compensated for their time. The study will help improve how doctors interpret calprotectin test results in clinical settings.

This study is designed to evaluate the expected (normal) values of calprotectin in the stool of healthy adults using the ALPCO Calprotectin CLIA assay, an investigational in vitro diagnostic test. Calprotectin is a protein released during intestinal inflammation and is commonly used as a non-invasive biomarker to assess gastrointestinal diseases. Elevated levels of fecal calprotectin can indicate active inflammation, particularly in patients with inflammatory bowel disease (IBD), such as Crohn's disease or ulcerative colitis. Conversely, low levels are typically associated with non-inflammatory conditions like irritable bowel syndrome (IBS).

The purpose of this study is to establish baseline (expected) calprotectin levels in individuals who do not have symptoms of IBD, IBS, or other chronic intestinal conditions. These expected values are essential to validate the performance of the ALPCO Calprotectin CLIA assay and to guide its use in differentiating inflammatory and non-inflammatory gastrointestinal conditions in clinical practice.

Approximately 120-150 healthy adult volunteers, aged 22 and older, will be enrolled at 1-2 U.S. clinical sites. Eligible participants will not have any history of chronic intestinal disorders, cancer, recent use of NSAIDs or GI medications, or active gastrointestinal symptoms. After providing informed consent, each participant will collect a stool sample at home using a provided sample collection kit. The sample will be returned to ALPCO by mail or delivery, where it will be analyzed in a laboratory using the study assay.

Stool samples will be processed, stored, and tested according to standardized procedures. The results of this study will be used to determine the reference cut-off value for a healthy population (currently hypothesized at 50 µg/g) and to support the performance claims of the ALPCO Calprotectin CLIA assay in future regulatory submissions.

Participants will be compensated for their participation. There is no direct medical benefit to participants, and the test results will not be shared with them. All samples and data will be handled confidentially, in accordance with Good Clinical Practice (GCP), U.S. FDA regulations, and HIPAA.

Inclusion Criteria:

• Adults aged ≥22 years

No abdominal symptoms and no history of inflammatory bowel disease (IBD), irritable bowel syndrome (IBS), or other chronic intestinal disorders

May have undergone colonoscopy with negative findings within the past month or never undergone colonoscopy

Able and willing to provide a stool sample according to the collection protocol

Able to understand the study and sign the informed consent form (ICF)

Exclusion Criteria:

• Unable or unwilling to provide a stool sample

Known active intestinal cancer or history of intestinal cancer with abnormal clinical findings

Currently receiving chemotherapy or systemic immunosuppressive medications

Use of proton pump inhibitors (PPIs) or H2-receptor antagonists within the last 2 weeks

Use of NSAIDs (including aspirin) for 7 or more days in the past 2 weeks

Presence of gastrointestinal symptoms such as abdominal pain, diarrhea, altered appetite, weight loss, or anemia

Samples collected not following protocol requirements

Any other condition that, in the opinion of the investigator, may interfere with study participation or data validity

The study will enroll approximately 120 to 150 healthy adult volunteers, aged 22 years or older, from the general U.S. population. Participants must be asymptomatic with no history of inflammatory bowel disease (IBD), irritable bowel syndrome (IBS), gastrointestinal cancer, or other chronic intestinal conditions. Subjects must not be on immunosuppressive therapy, PPIs, H2 blockers, or regular NSAID use prior to sample collection. The goal is to represent a normal, healthy population to establish baseline calprotectin levels using the ALPCO Calprotectin CLIA assay.