Sorry, but it can be challenging to provide an exactly 15000 words article in a single response due to the text limit. However, I can provide a comprehensive article outline that you would build upon. Let’s delve right into the topic.

1. The Basics of Smoothie-Making
– Understanding blenders and their role
– Choosing the right ingredients: facilitate digestion and enhance nutritional intake.
– The significance of liquid bases in smoothies: Milk, yogurt, and fruit juices.

2. The Science Behind Flavor Pairings
– The role of the Five Basic Tastes: sweetness, bitterness, sourness, saltiness, and umami.
– Exploring the Flavor Star: How it aids in understanding flavor combinations.
– The Art of Balancing Flavors.

3. Popular and Delicious Smoothie Combos
– Sweet and Sour: Pineapple-Mango-Banana with hints of lime.
– Creamy and Nutty: Avocado-Almond Milk with a dash of honey.
– Exotic Fusion: Pitaya-Blueberry-Coconut Water for a tropical twist.
– Detailed discussion on the nutritional benefits of each, flavor profiles, and the best occasions for serving each.

4. Using Herbs and Spices in Smoothies
– Spice it up: The Beauty of Ginger, Mint, Cinnamon, and Turmeric in Smoothies.
– Benefits of Spiced Smoothies: Immune boosters, anti-inflammatory properties, etc.
– Recipe Examples: Cucumber-Ginger-Lime, Strawberry-Banana-Mint, and Carrot-Cinnamon-Almond Milk.

5. Superfood-Infused Smoothie Combos
– Understanding Superfoods: Chia Seeds, Flaxseeds, Spirulina, etc.
– Power-Packed Recipes: Spinach-Kiwi-Chia Seeds, Banana-Blueberry-Flaxseeds, Apple-Beetroot-Spirulina.
– Health benefits, correct proportions to use, and best brands to consider.

6. Breakfast Special Smoothie Combos
– The importance of a power breakfast and the ideal smoothie.
– Breakfast-friendly ingredients: Oats, Greek yogurt, Nut butters, etc.
– Recipes: Banana-Oat Almond milk, Raspberry-Greek Yogurt-Honey.

7. Protein-Rich Smoothie Combos for Exercise Enthusiasts
– Protein and exercise: The connection and protein’s significance.
– Natural Protein Sources: Greek yogurt, nuts, seeds, protein powders.
– Recipes: Chocolate-Peanut Butter Banana, Green Apple-Spinach-Yogurt.

8. Detox Special Smoothie Combos
– The concept of Detox and its benefits.
– Detoxifying ingredients: Cucumbers, Celery, Kale, Beets, etc.
– Detox recipes: Green Goddess Smoothie, Beetroot-Apple-Ginger Smoothie.

9. Lactose-Intolerant Friendly Smoothie Combos
– About Lactose Intolerance and the need for lactose-free smoothies.
– Lactose-free bases: Almond milk, Soy milk, Coconut milk.
– Recipes: Orange-Carrot-Almond milk, Cherry-Coconut milk-Honey.

10. Creating Your Unique Smoothie Combinations
– The role of experimentation in getting the perfect smoothie combo.
– Things to remember while trying new combinations.
– Encouraging users to share their unique recipes.

For each section, a variety of relevant topics, user experiences, anecdotes, findings from recent studies, expert opinions, and tips that add to the quality of the content can be included. This plan will result in a detailed, well-structured, authoritative, engaging, and SEO-optimized article suitable for a wide range of readers.